I'm traveling a lot this summer, and I invited myself to visit and give talks at a couple of universities in other countries.
Do I list these talks on my CV? If so, under what heading? They're not exactly "Invited Talks." I don't have a general "Talks" section on my CV because I want to exclude conference presentations (which are already represented as publications, and which nobody lists in my field). I could have a "Seminars and Colloquia" heading, but people might assume these were invited.
If you discover that a friend in a distant city is having a birthday party, and you ask "Hey, can I come?" and they say "Sure!", you've been invited to the party.
Same thing goes for talks. When the host institution agreed to let you talk, that was your invitation, which makes it an invited talk.
That said, you may want to distinguish plenary talks at conferences and formally organized departmental colloquia from random seminars run by individual faculty.
What you list on a CV depends on the purpose of the CV. The idea that you have a single CV isn't really accurate. For example, using an NIH CV/biosketch for a job application would not be a good strategy. I believe that a "long" CV should have everything on it. I add things to my long CV as I do them which makes creating shorter CVs tailored for a particular purpose much easier since deleting is much easier than adding.
There are many things for which there is a benefit of listing talks that you have given at other departments/labs on the CV, the issue is really what "heading" they come under. The most critical thing when divining things up is that each item on your CV can only be listed once. You cannot list a conference you attended, gave a talk at, had an abstract published for, and a paper published for four times. It can only go on the CV once.
I try and only divide things into sections based on "concrete" criteria. It is clear when you are giving an invited talk at a conference, but it is not clear whether a departmental talk is invited or not. Similarly, it is not always clear whether a departmental seminar is a job talk or not.
The relevant sections on my CV are (a) Conference Papers, (b) Conference Abstracts, and (c) Research Presentations. Each "presentation" only goes under one category. I limit the "abstract" category to conferences that produce archival abstract books that people have a fighting chance of finding. Talks and poster presentations at conferences that don't have archival abstract, departmental seminars, talks to research groups, and job talks, go under "research presentations". I have a separate teaching presentations section for teaching based job talks.
I split the papers and abstracts sections into posters/talks and invited/submitted (someday hopefully I will add key note). The presentations I split into internal and external. I like to keep track of my internal presentations for annual review CV since it lets me demonstrate departmental citizenship. I tend not to split the presentations into posters/talks or invited/submitted since as I mention before, it is too difficult.
Younger faculty (with smaller vitas) tend to include less prestigious colloquium talks on their vitas. More established faculty, who have longer lists of more prestigious talks, may just have one line saying "colloquia and seminar talks at many universities." (That's a real example from a senior professor.) I tend to agree: if you have done something, you don't want your vita to suggest you've done nothing.
The main thing I tell my students is that a vita has to pass the "straight face test". If someone asks you in person whether some line "truly" deserves to be on your vita, you need to be able to justify it with a straight face. This is also how you know whether to include e.g. prizes that you won as an undergraduate: when you can no longer justify them with a straight face, it's time to remove them.
As long as you can do that, it's unlikely anyone will press you too hard on it. Other people in your field will understand how things work, so the main goal of the vita is to present yourself clearly to them. They can make their own judgement about the value of each activity. Unless you can't include something with a straight face, you can only hurt yourself by leaving out "minor" activities.
