Multiple displays with an Intel Macbook Pro

Hi,

I've searching a lot, and I haven't find a way for having an external LCD display plugged to my Intel Mac Book Pro without buying Matrox DualHead2Go.

I bought and adapter that I use with a projector when I'm in a meeting (VGA to Mini-DVI I think...), but when I use the LCD monitor with this adapter it's simply not recognized. Is this a software or hardware problem?

I'm using Snow Leopard 10.6 and I'm wandering if there's a solution for this or if it will be possible until Lion Update...

Thanks in advance