I know some PhD students have their own business cards, but I don't know if it is a standard practice for PhD students to have their own business cards. I think a business card can be useful for networking in conference or collaborating with some industrial partners. So, is are business cards necessary for a PhD student or other graduate students attending conferences?
PS: in case it is field-specific, I would like to know the different practices in different fields
It's probably discipline-specific, but I hand mine out all the time. That being said, I talk to lots of vendors of computer hardware that I want to get back in touch with, so exchanging cards is helpful. As a grad student, it might be worth having some small cards from someone like Moo that have your name, email, affiliation, and a link to your website. It might be easier to hand those out than to carry 20 preprints of your article when you're giving a talk.
All that being said, it'd be pretty unusual to push your cards on people you meet at conferences. If someone asks for your information, or a copy of your publication, you might offer the card, but I wouldn't volunteer it unless you've been asked for something. It's just not part of the culture in most of the fields I have experience with for students to do so.
As a PhD student, I had business cards and never used them. Now I don't even have cards. I consider them a relict from different times. I would say nobody strictly needs a business card anymore, and I rarely see them being exchanged at conferences either.
Now, a homepage is a different story. You definitely need a homepage, for many of the reasons you think you may need a business card.
If there's any chance that you're going to be interacting with industry at conferences or other events, you need business cards. It's part of that culture. If there's any chance you'll be interacting with anybody from the far East, you need business cards (and ideally, a briefing on the etiquette of giving and receiving them).
Within academia (and not in the far east), it may depend on your field. Coming from a commercial background I was surprised to find that they aren't used in the same "scattergun" way in mine; but it can still save time with scribbling details, and a good card, offered appropriately, may make meeting you stand out in the fog of somebody's post-conference memory.
Summary: it's worth having some, but try to judge what is "normal" before pressing them on people.
This probably varies from country to country, but given that business cards can be had for the cost of running off-the-shelf preperforated stock through your computer, I think it's worth having a few. It does make handing your contact info to someone easier, plus giving you and/or them a surface upon which to scribble a note about why they should contact you.
And at least around here, many restaurants collect business cards as tickets for a free-lunch lottery. Trade shows may also use them as lottery entries.
Yes, e-mail addresses are starting to replace business cards as e-mail becomes an acceptable replacement for postal mail and phones, and smartphones can be used to enter contact info into a website.... But it isn't a complete replacement yet, and may never be.
And I find I use them informally as well, when I want someone I've just met to contact me about something.
Recommendation: Spend a small amount to print off a few, see how quickly you're using them, use that to guide how many more you obtain, how often, how many you should bother carrying at once, and how much effort you should put into the card's aesthetics.
In 15 years in academia (theoretical computer science, UK and Greece, plus conferences and workshops in several different countries in Europe and North America), the closest I've come to a business card was when somebody I'd befriended at a conference gave me a card for his hobby photography website. I've never had business cards printed and, to the best of my knowledge, nor have any of my colleagues.
In the US, at least in doctoral psychology programs, we're often encouraged to have business cards to hand out at conferences. Conferences are often seen as a way to start building connections for internship, and a business card is a simple way to come across as polished and prepared (it's also less likely to be lost than a slip of paper, as I've seen faculty slip my card into a card holder). Further, my mentor does a great deal of field research in health clinics, and it's helpful for her students to have cards with their contact information readily available when coordinating with site staff.
In my department, our academic mentors typically pay for the cards, which are designed with the school's logo, just like the faculty members' cards. However, most of us wait until we have received our MS as part of our program requirements. We don't attend as many conferences pre-MS anyways, and since they're ordered in bulk (250 minimum) that way you don't have a large number of unused cards. In sum, it's not necessary to have business cards, but it can be helpful.
This may depend on the country. In some countries, PhD candidates are employees of the university just like anyone else employed there, and thus get (or can get, upon request) any number of business cards printed from their office supplies department at any time. Thus, in such places, the effort of getting one's hands on business cards is virtually non-existent and hence there, it is a standard practice.
As implied by other answers, handing out business cards greatly simplifies establishing contact with other researchers on conferences, which is one of the main benefits one can draw from attending a conference.
In terms of establishing contact, I have only ever met two kinds of people on CS conferences - those that had their business cards ready and could thus easily provide some contact info at the end of a fruitful conversation and the agreement to keep in touch or exchange some further information, and those that did not, that would instead start a cumbersome search for something to write, use the back of someone else's business card (!) or require the recipient to find some suitable virtual place in whichever electronic device they currently have nearby to store the address, and remark that they "should really print some business cards for the next conference".
I'm in the biomedical and clinical sciences (Epidemiology in particular) and I regularly hand out 5 to 10 business cards at the average conference I've gone to, and often get just as many. I tend not to actually engage with industry that much, but they're an excellent, quick way to give someone your contact information in a way that's about as non-disruptive as possible. They're also harder to lose than scraps of paper, and as someone else mentioned, easier to keep track of - business card holders can not only hold your business card, but the cards of others.
