I enjoy taking part in the regular Speed Modelling Challenges (SMCs) on the Caligari Truespace Forum. The rules are pretty simple - create a model on the theme selected (by the previous winner). Modelling must be achieved in 2 hours, but texturing, lighting and rendering time aren't restricted, so as not to prejudice those with slower computers, older versions of the software, less fancy render engines, etc. Forum members then vote for a winner. I've entered a number so far and although I rarely get many votes, I've enjoyed the challenge of coming up with models I wouldn't otherwise consider and learning new techniques. Below are my SMC entries to date.