Currently I'd just get some Mopads to isolate them somewhat from the desk (they're not going to do much for the lowest frequencies) - if you can get hold of a couple of 1/4 inch steel plates to sit on top of the Mopads, even better (copying the much more expensive Recoil Stabilizers for less money), however stands would be much preferable for the simple reason that not only do you get a bigger listening triangle, but you avoid desk reflections and can move the speakers away from the wall a bit (I take it they're rear-ported) so they have more room to breathe. I'd also look at buying some acoustic treatment kit as well - bass traps for the corners etc, although it really depends if you're cranking them as it's a bit OTT for low-volume listening.
Stands are pretty easy to DIY - there's some good cheap designs on the web, and you can re-use the Mopads for them too. Generally speaker stands are ridiculously overpriced for what they are so it's worth having a stab at doing them yourself.