cutting aluminium

For those of you that build telescopes out of aluminium parts, what kinds of tools/blades/bits do you need to cut aluminium sheet or "L" stock.

Harbor Freight Tools sells a special metal-cutting bandsaw for $200. It works great on steel and aluminum. The blade runs at a much lower speed than a wood bandsaw, which is what you need for cutting metal without a coolant or lubricant.

Also, a metal cutting blade for a hand-held jigsaw works too. Its not as pretty as a band saw cut, but as Mitch said, it can be touched up with a hand file.