I have SL installed in both operating systems...was a bit of a hassle to get it working in Linux (due to 64 bit issues) but it works fine now, even with sound, and voice. Just mess with the secondlife script that starts it to make sure gstreamer doesn't get disabled
#if [ "`uname -m`" = "x86_64" ]; then
# export LL_DISABLE_GSTREAMER=x
# echo '64-bit Linux detected: Disabling GStreamer (streaming video and music) by default; edit ./secondlife to re-enable.'
Don't create that SLVoice script some say to do. Just get all those i686 libs you need.
I'm also in counseling working on getting the "hormone letter".