I just wanted to add a couple of things...
1. I'm sure you don't want to have a lapse in coverage for obvious reasons, but as far as the pre-existing clause goes, you are allowed a 62 day lapse for which they cannot penalize you (by federal law). If you have a 63 day (or greater) lapse, your new insurance company is then allowed to put you on a pre-existing condition clause. The greater the lapse, the longer he waiting period.
2. As a couple of other people said, many insurance companies now insure domestic partners (some only insure same sex partners and some insure both so if that's the route you take, make sure they insure both).
3. In most cases you can stay on your parent's insurance indefinately if you are disabled (not sure what the standard is to prove that, however) but it may be worth looking into...
Good Luck whatever you decide! Ironically, I just watched the Michael Moore documentary "Sicko" last night and literally sat here and cried at how bad our healthcare system is in this country. We are the only civilized and wealthy country in the WORLD that doesn't have socialized medicine... That documentary is really eye opening. I wanted to pack up and move to France by the end of it...