I use to gig every weekend with 2 keyboards - one was a midi controller that triggered sounds in my computer, and the other was a simple Yamaha YPG-235 keyboard I got for something like $225 brand new.
 
The Yamaha keyboard was also used to trigger sounds in the computer, BUT, it also served as my backup sounds anytime the computer threw a hissy fit, because of its local (on-board) sounds.
 
Its general sounds - piano, Rhodes, strings, Clavinet, etc. sounds worked just fine for the band I was in, and that thing saved my behind many times when power problems or general computer glitches caused me to lose sounds at gigs.
 
It was also 76-keys and quite light to carry.
 
Bob Bone
 

All this feedback is very helpful, thank you all.
 
Right now there's a a MicroKorg at a really good used price at my local GC.  I'm finding MiniNovas for around the same price online - I wouldn't have the chance to test the MiniNova like I will with the MicroKorg: any thoughts on the comparison between the two, if any?

Played the MicroKorg today at GC and fell in love.  The perfect solution to my problem and so much fun - thanks to everyone who offered up help.