working with plexiglass

As you've already mention, for straight cuts, easiest thing to do is score and snap.

You can use dremels, scroll saws and routers but it tends to melt the plexi at high speeds due to friction.

Don't forget to wear safety glasses

^ YEP^ .......Score and snap works great on the thin stuff. You can also cut thicker stuff on a tablesaw with a plywood blade mounted backwards. Put masking tape along the line you want to cut to prevent 'blowouts', and have the blade just barely higher than the thickness of the plexi. As PHI mentioned above, you have to be carefull about melting it tho'...(Going to slow etc)
Also to make the edges clear after cutting, carefully run a flame (ie; torch) along the edge till it just starts to melt. when it cools it will be clear.
MCTOY

a fine tooth blade works fine. get a hand saw with fine teeth blade. Cuts smoothly . You want to get the finest one cause if they are wide and too big you might just crack the plexi.