Can't afford a TB-303? No fear, it's been replicated on the internet (kind of).
Thanks to Errozero, Acid Machine's developer, you're now able to produce some acid house jams at the click of a mouse.
No need for studio space or to delve into your savings, it comes armed with a couple of bass synths, a drum machine, a randomise function and a few more settings.
Although it's still in development, you can use it now and all you need is a half decent computer and Google Chrome for the best results. Have a go here.