Speaker Platforms for Desks (clampable and adjustable)?

[corinthos]

I have a computer table I got at Office Depot that I'm planning to put a 37" LCD TV monitor on, which will take up most of the width of the desk, leaving no space for my bookshelf speakers. The computer table is perhaps laminated board that's 1" thick. What I'd like to do is to clamp to the sides of this table a couple of platforms that are large and strong enough to place my bookshelf speakers onto them stably and safely (not going to fall over, etc). I have in mind something similar to monitor arm mounts with clamps, except made to accommodate speakers as speaker stands of sorts. I'd like to be able to adjust them by pulling them towards the desk and pushing them back out as needed. Is there such a product or easy way to put together my own without doing any mods (just buying parts and putting together only)?
Is there such a thing I can get cheaply? If not, I might just go with some cheap speaker stands instead.

Thanks in advance.