Newbie needs info on modest laptop speakers

Are you thinking of desktop monitors or speakers to actually fill a more or less large listening room with (or something fulfilling both requirements)?

Anyway, if you intend to build a system consisting of only your laptop and a set of speakers, take a look at this active monitor, that I found quite amazing in terms of speed, dynamics and detail (which is how I interpret "gotchas").
http://www.adam-audio.com/downloads/A5_bulletin2008_150dpi_engl.pdf

Then again, any advice is dependent on another question, though: your budget please?

NHT S00 and NHT M00

Karelfd is right..for instance, if budget is no issue, then...

http://www.headphone.com/products/audiophile-desktop/

If you're strapped for cash and are limited to mass market products, these are widely available, sound okay and if you're a Sam's Club member, only $70...

http://www.bose.com/controller?url=/shop_online/speakers/computer_speakers/companion_2/index.jsp

Then there are plenty of solutions that fall in between...for instance...

http://www.zvoxaudio.com/cgi-bin/Make-a-Store.cgi?item=4002215&add=1

Let us know budget, size restrictions, whether you're willing to visit a speciality store to purchase, etc and we can make some further recommendations.

What I use at home and at work are the Klipsch ProMedia powered sat/sub combo. You just connect it to your computer via the audio out and adjust the volume through the left speaker knob or iTunes. I was able to buy these for under a $100 per set, but I think they have been discontinued.

If you want to spend a little more for better performance consider the NHT powered PC speakers.

http://nhthifi.com/current/products/pchifi/m00.html

Good luck!

Here's a good solution for about $450: Devilsound USB DAC and some Audioengine A2 speakers. I am using the Devilsound DAC in my main system, while my Wavelength DAC is in the shop under going some changes, and the little Devilsound is quite good! At my office I use the Audioengine A5 speakers and thay are very good. And, I've only read positive stuff about the A2's.

What do mean "gotchas" as in low wattage speakers?