After getting my second-hand mac mini a while back, I used SuperDuper to make a bootable Snow Leopard volume on a USB memory stick because I had no Install disc.
Well, having used Xbench to test read/write speeds on the internal HD, an external HD and two memory sticks I realise the bootable volume is on the slowest. Never mind, it works and it's there just in case I need a near-fresh install. Will probably never use it, but in future I should buy better ones if booting them.