Just buy a decent digital metronome, they arn't much money.

I have one that cost me about £12 and it does 4/4,3/4,2/4 from about 60 to 240bpm and tunes to A, that'll do for the basics. I'm not sure if there are any digital metronomes that do more interesting time signatures though, such as compound time sigantures... I guess there must be.

- J