Well, I appear to be in the fairly enviable position of having too many job offers (all but one of which being unsolicited - kind of) for the summer (and beyond). There are (if no more drop in by then) four "possibilities" (loose usage of the word).
The first of which is a summer internship at City of Hope. This would make a great resume-buff-upper, and may be educational, doing real research at a real medical research facility. However, I'm betting it wouldn't at all be like some of the classes I actually enjoyed going to at school (microbiology and immunology come readily to mind; I actually would enjoy being in class, though not so much the labs, homework, and tests), and I suspect it'd probably be nothing more than some mind-numbingly boring thing like running gels all day long for somebody or other's experiment (a typical entry-level biology job). Ultimately, I decided against this, based on the presence of more interesting possibilities, and the fact that, unlike all the others, I'd actually have to formally apply (and competition is fierce - only like 1 in 50 applicants get internships).
Next is the company I worked for last summer, and have been working a little bit for over the school year. As far as I'm aware, they still want me back, next summer and/or full time in the future. It's a really nice place to work for, though it's either the #2 or #3 spot on the list for most interesting/appealing work.
Next is... let's call them Company X (saying which would only incite replies of "WTF liar!" and "Bastard, I want to work there!"). As that implies, this is undoubtedly the most interesting and potentially fun job prospect (although I have no idea what the work environment is like). Last summer I got an "invitation" to work for this company, when I was sending my semi-regular research to a friend there, who is a programmer (thus, it wasn't a formal invitation, though as he has some sway, I would surely have a much better chance of getting hired than the average applicant). Unfortunately, it took almost a month to get an interview set up for me (it's not his fault, either. I sent him ping e-mails once or twice a week, and all he could tell me was that they haven't responded to him yet), and by that time I'd given up waiting, and was already in Kansas, working for my current company (the main reason I didn't wait longer was because I'd already told my company that I'd work for them, if the thing with Company X didn't work out, and I didn't want to make them wait any longer than I already had). This is probably my #1 consideration for what to do when I finish college; however, I'll probably put off trying again until I finish college, and just apply for a full-time position (rather than just summer work).
Finally, tonight my computer architecture II (senior-level class) teacher scouted me out for a future project somehow relating to him. He hasn't told me much yet, just that it involves something about computer simulation of neuro-something or other (maybe neural networks, or some such). This one could really disturb my plans of going back to Kansas this summer, if the project turns out to be interesting (when I learn more about it) and there's a monetary advantage to doing it, instead (since I wouldn't need to pay rent out of my earnings, like I would in Kansas).
So... I'm not at all sure what I'm gonna do this summer. As of right now I'm planning on going back to Kansas; but if there's a monetary advantage to taking the job with my teacher (and the job is interesting), I might be inclined to do that, instead. Time will tell...