marble tile countertop (Attn. 2vernes)

2vernes (and, of course, anybody else who may be interested!) -- I didn't want to hijack Staceysmom's thread with her amazing countertop paint job, but I did want to address your question about marble tiled countertop.

It's a do-able DIY job if you have a little patience and the right tools.You're right-- you can get a nice stone look for a fraction of the price of a slab.
I made a travertine tile countertop for a 6' bathroom vanity (what I used would be too fragile for a kitchen, but granite, as you mentioned, would be much better). It wasn't terribly difficult, but I've got a good wet saw (they can be rented, too) and have done quite a bit of work with stone. The most difficult part was cutting the pieces that went underneath an oval sink.
I've also done a granite tile hearth top/fireplace seat that's pretty much the same as countertop. I'm in the process of putting in a marble tile countertop for a rec room bar area, too.

I wouldn't put the tile just over plywood; there's too much flex, and if you get any little leak it will soften the plywood. I'm not sure how well the mortar would stick to laminate, either. I used Durock (cement board) over plywood. I'd also recommend leaving at least a 1/8" grout line to seal the edges. Butted edges might make your marble look more like a single piece, but you don't want moisture (or food bits--ew!) working its way in between the tiles.

Another "voice of experience" recommendation-- before you mortar down all the tiles around the sink, find out how much room your plumber (or you, if you do plumbing) will need for connecting the faucets. I left plenty of room for the water pipes, but it turned out the connectors were quite a bit larger than the pipes. I had to break out a tile after everything was already mortared down and grouted & cut a new one to fit.
Good luck with the project if you decide to go ahead with it!