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?
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?