I am looking at graduate schools and one of the things I would like to know about the schools I'm looking at is where recent graduates are now. I realize that contacting the colleges individually would certainly work. However, there are a lot of colleges out there, and it is untenable to ask them all individually. Is there a place where this kind of thing is available online?
If your looking at PhD's who presumably wanted to go on to academic careers, and if you can get a list of the graduates from a particular year, then you can generally track those people down by searching for them using Google. Most people who've remained in academia have at least some presence on the web. Folks who go to work in industry often become invisible.
The hard part is getting a list of graduates from a particular year. This can sometimes be done using commencement programs. I have done this using the mathematics genealogy project at:
Despite the name, this database has records for computer science, mathematics, and statistics graduates from many institutions. You can search by institution name and year of PhD (e.g. I'm Rensselaer Polytechnic Institute, 1992.)
If you're looking for graduates who went to private companies, you may try LinkedIn. In theory, the private companies' keep their list of employees private. With the heavy use of LinkedIn, it's easier to search for people who went to certain schools and work/worked at certain companies. The problem is that the information is not readily available to people who don't have any connections to the schools and the companies.
Of course, there are always people who are so private that they don't sign up for LinkedIn.
Is there a place where this kind of thing is available online?
No. Not to my knowledge.
Some departments list where (some) of their graduates go after finishing their PhD. Your best source of information is your potential advisor webpage. Some professors mention where his/her PhD students go after finishing their degree while others mention only the names.
In the latter case, one simple way is to Google their names; you may get an idea where are they now. Another is to look for your potential advisor recent publications that are co-authored by his/her graduated students. You may know where are they now by their affiliation.
If you still do not have a potential advisor, a random sample over the faculty members in your department may be sufficient.