If it's a laptop, I assume you take it with you at times... Why not a pair of nice headphones? I just bought a pair of Grado SR80s (under 100 clams) and I'm damn impressed of the sound I get out of my iPod, eMac, and iBook. Really damn good. Much better than a cheap stereo, and portable.
If that's no good, I saw emagic 2|6's on sale for $99 at Sam Ash. I used one to run digi out to a DAC for awhile--the sound was pretty damn good! It has both digi and analog out, IIRC.