Cutting acryllic
From TheBestCaseScenario
Cutting acrylic is easier than you might think. If you'll do your research you will find that there are special blades for table saws and radial saws that are designed for acrylic and plastic. They have special teeth with certain angles and degrees of rake, etc etc. While I am certain that these blades will cut acrylic very well, and will leave you with less cleanup to do on the cut afterward, they are prohibitively expensive for me, so I will share what I have used.
For my table saw work I use a 7 1/4" Freud Diablo 40-tooth carbide combination blade. They can be found at your local Home Depot (or various online sources I am sure) for about $15, and I use them for everything. Mine is mounted in a 10" Grizzly table saw, and while it looks small in that big saw, it has several advantages over a 10-inch blade. It runs quieter, spins up faster, cuts cleaner (wow!), is less likely to bind up in the work, and is half as thick as any 10-inch blade you'll find, so there's half the waste and half the mess. Buy one.
The best way I have found to cut circles out of acrylic sheet it with a double-tooth circle cutter in the drill press. They can be found at http://www.grizzly.com/products/Adjustable-Circle-Cutter/G8964. They CAN be used in a hand-held drill but it is difficult and dangerous. Smaller holes (2" or less) can be better cut with a Forstner bit, available at Harbor Freight or just about any store that carries wood tools. They cut very easily and leave an excellent finish on the sides. Don't use expensive ones, though, as acrylic will dull steel tools pretty quickly. For anyone who is not familiar with these, a pic can be seen at http://www.harborfreightusa.com/usa/itemdisplay/displayItem.do?itemid=94212&CategoryName=&SubCategoryName=
Cutting non-circular holes out of acrylic sheet (for power supplies, motherboard trays, etc) is easy with the right setup. I am blessed with a large router table. I mark out the holes I need to cut and drill a hole in the corners. Then I take a 1/4" to 1/8" router adaptor that I got for $10 at Sears and put a standard Rotozip spiral cutting bit in it and in the router. Lay the acrylic over the spiral bit and put it through the hole, move your router table fence up against the side of the sheet, turn it on and cut. Cuts like this are fairly smooth, and perfectly straight. The only drawback is that you can't cut square corners like this because you're using a round bit, but it's only 1/8" across to the corners are only slightly rounded. If you don't have a router table you can do the same thing bu using a piece of scrap as a fence. Measure the distance from the edge of your router base to the edge of the Rotozip bit and clamp your scrap that distance from the line you want to cut. Make sure it's the same distance on each end of the cut line and keep a firm grip on the router to make sure it rides on the scrap and it'll look just like a cut made with a table.