I interupt this thread for an important service announcement.
Missed your Anon face my Hawtness.
OK, now on to topic, it is very likely not you, or not just you.
The last few weeks/months have been bad for a lot of people, from lag to crashing to inventory issues.
There is a thread here about it, with a few tips that might help.viewtopic.php?f=55&t=6447
The reasons and theories seems varied but tend to come back around to a) new viewers suck b) mesh is the problem c) open GL issues d) the Lab is the problem.
The quick and dirty (cause I know you like it like that) uninstall ALL your viewers totally, clean sweep. Having multiple versions of both V1 and V3 viewers has been linked to some of the problems. Then install Exodus. http://exodusviewer.com/
It's really, and sadly, the only way I can enjoy SL right now. Not my viewer of choice, but it's better than swimming in jello blindfolded with rubber bands on my feet.
There is always a chance it's your computer or video card, but give that a try first.