Just for kicks, I installed Debian Woody on a Sun LX50. It worked just fine, and I expected it to. The Cobalt group within Sun really has used commodity Intel server hardware to assemble this beast. And they've done a very nice job.
Once I'm done playing, I can put the Sun Linux restore CD in and bring the system back to "factory defaults" with Sun Linux installed once again. The whole process takes maybe 20 minutes if you're attentive to changing CDs (there are three of 'em).