I've been thinking of the same. Some random (and maybe incorrect)
thoughts :

Get a video card with dual monitor out. That way you can hook the
laptop upto a bigger monitor. Maybe plug in a USB keyboard at the
back... and it works as a desktop. I don't know if this is practical
but I think it should work.

The downside of laptops is that you pay through your a$$ for something
you will be using mostly as a desktop. Do you really need the
portability?

It is nice to work a project on a laptop mind you. Very nice...
ahhh.... I wish i could have one.