Kernel
panics, methinks, Rob!

I've only ever had one - and it wasn't all that exciting, for something named "panic." Anyway - have you done anything new in the last ten days? Installed new programs?
What exactly are you doing when the panic occurs? Was it the same thing both times or something completely different?
Anyway, here's a good troubleshooting-a-kernel-panic advice page:
http://www.thexlab.com/faqs/kernelpanics.htmlKernel panic definition from WikipediaQUOTE
The kernel panic was introduced in an early version of Unix, and demonstrated a major difference between the design philosophies of Unix and its predecessor Multics. Multics developer Tom van Vleck recalls a discussion of this change with Unix developer Dennis Ritchie:
I remarked to Dennis that easily half the code I was writing in Multics was error recovery code. He said, "We left all that stuff out. If there's an error, we have this routine called panic, and when it is called, the machine crashes, and you holler down the hall, 'Hey, reboot it.'"
One thing I'd advise doing right off the bat is repairing permissions using Disk Utility.