This is something I heard about on a blog belonging to somebody I shall refer to, somewhat coyly, as 'Mr.Lewis'. Basically, you give yourself a set time frame- I went for 10 minutes as I'm still fairly weak but he recommends about 20- and you do as many singles of a full-body exercise- I used the clean and press, typically- in that time.
It's some of the best fun I have ever had lifting weights. The best thing is you're not wasting time resting between sets. You're resting as little time as it takes for you to recover enough for another single, and you push yourself hard to get as many singles in as you possibly can.
The best part is that you can give yourself a score- weight multiplied by total reps divided by time, and I can confirm the truth of the crossfit adage that 'men will die for points'.
Anyone else ever tried it?