I've seen alot of posts about people wanting the fan test for their 60 GB PS3s, and yes there is a way! Simply turn your PS3 on normally and hold it vertically in midair with the vent side facing down. Wait 10 to 15 seconds (depending on how hot your PS3 was before) and it will begin to cycle through the fan levels to its highest while blowing any dust out of it.
After 15 to 30 seconds of this, or until it warns you that your PS3 may be over-heating (It thinks it must be over-heating because why would the fans be on so high? When in fact it is just fine), just place it back down in its horizontal position and the fan will go back down to normal.
I did this twice to my 60 GB, not sure if it works for 80 GB please let me know, and it certainly cleared alot of dust out. I'd say its safe to do once or twice a month without causing too much stress on the fans, and I base that on absolutely nothing. ENJOY!
(warning!!! don't try if warrentie is still in affect.)
EDIT as requested: