the university park hotel is very nice, but, as you said, it's also rather expensive (in general, but even more so if you hit it at the wrong time, like parents' weekend or finals week or graduation week or something like that).
as for the area, that would be MIT campus. campus is cool (well, it's mostly one sprawling grey concrete building, but there are some cool places in and around that building), but there are some not so nice neighborhoods nearby. i haven't been through northern cambridge very much, but i've walked around near campus and the hotel and i've talked to people who've lived up that way (for example, in the sort of off-campus dorm that's more or less around the corner from the hotel). in general, let's just say that the area between MIT and harvard has seen better days.
personally, if you're going to be staying in boston (and i'd definitely reccomend doing so.. boston is probably my favorite city in the country), i suggest copley square. it's more or less central, there are plenty of hotels in the area to fit plenty of different budgets, and there are several T stations close by.
(the T is the boston subway system... the transportation of choice for getting around the city and its immediate suburbs. clean, safe, prompt, and lets you avoid the boston streets. the boston streets were quite literally designed by meandering cows being led to and from boston commons, which used to be a public pasture. the cow paths became trails which gradualy became roads. they rarely go in the same direction for more than 2 blocks, and most of them have been randomly designated as one ways. worse, they're filled with boston drivers who have only 2 discernable rules. 1: stop for pedestrians. 2: if you're in a car, it's your responsibility not to get hit.)
anyway, we've had good experiences with the
westin copley place hotel. actually, some years back my sister called to make a reservation. she asked for their rate. don't remember exactly how the conversation went, but it was something like this:
"... and how much will that be?"
"$200 a night."
"uh-huh. do you have anything cheaper?"
"hmm... let's see... yes, i have the same room on special for $175."
"do you have anything cheaper?"
"let me check... yes, i have the same room at a super saver rate for $160."
"do you have anything cheaper?"
"<surprised> actually, yes..."
... and 10 mintues later we had the same room on a special rate only available that weekend that came to about $80 a night. not sure if that sort of thing will really happen anymore now that there's priceline and expedia and everything to do that for you, but it never hurts to ask.
anyway, if it's not to your liking or if you can't get a good rate or something, i'd check around in that general area (copley).
Paul