So much more has surfaced since the original post that I felt it was worth posting a follow-up (plus, holiday weekend in the US = slow news day...). This was part of another post from someone, but lo and behold, Geordi LaForge had a 'security' gig before becoming a helmsmen, and then an engineer, on the Enterprise-D!

What else can you find? Here's the original thread:

http://observationdeck.io9.com/trek-actors-on...

I would also add Tasha Yar in a sex comedy with John Ritter (which also featured a brilliant, er... "lightsaber" duel...

UPDATE! Speaking of Tasha Yar, I stumbled across this today (I'm a Chris Isaak fan, so I wasn't looking for the Trek cameo): lo and behold, SCANTILY CLAD YOUNG DENISE CROSBY! You're welcome, Internet!