I would standardize them and simply put the most relevant information on them.

• University + department, perhaps down to room number
• Personal academic homepage
• E-mail address
• Phone number
• The fact that you're a PhD student or so.

I wouldn't add too much information on them. Business cards are for core info, nothing more.

I would standardize them and simply put the most relevant information on them. My (dated) business card looks like this:

Now I think it has a little bit more information than needed; fax is almost certainly not needed, but there might be circumstances where it's handy to have the mailing address. But important are:

• University + department
• Academic homepage
• E-mail address
• Perhaps phone number
• The fact that you're a PhD student.

I wouldn't add too much information on them. Business cards are for core info, nothing more; they might get crowded otherwise.

My own business card is outdated: a university reform means I'm no longer at the Department of Space Science, but at the Department of Computer Science, Electrical and Space Engineering, Division of Space Technology. But I don't care, because the e-mail address is still correct, and the new department/division wouldn't even fit on a business card ;)