People in the western United States, north of central California, will have a chance to watch the Stardust spacecraft reenter the Earth's atmosphere in the early hours of Sunday morning.
This site has some additional viewing information. For people like me in the San Francisco Bay area, you need to look very low in the sky to the north, starting around 10 minutes before 2 a.m.. The weather looks kind of difficult for viewing here so I will just have to see how it works out.
Sadly, the last time I watched for a spacecraft reentry was in February 2003, when I watched the shuttle enter the atmosphere from a viewpoint in San Francisco. It looked like a very bright long meteor, and I didn't notice anything wrong. I went back to bed and then found out the next morning that the shuttle had disintegrated minutes after it disappeared over the horizon.
Compared to that, the worst case scenario for Sunday is no big deal.
UPDATE: well, I saw nothing even though skies were clear - the same result as with other space nuts I know who went out to watch. But it landed safely, which is the important thing.