Sudoku rules!

Not content with the one version of Sudoku on my Palm, I keep visiting Palmgear in search of new versions which might suit the way my brain works better. There are now several versions available there - and another version is about to be released by the games people Astraware and so excited by that am I that I have put my name on the "notify" list.
I am spending far too much time with Sudoku - as evidenced by the timers that are now routinely included in the Palm versions. I keep thinking "I'll just have another game and see if I can beat my last score" and then I am trapped for another 10, 20, 30 ... minutes.
What surprises me most is how Sudoku puzzles can be so different (not to mention difficult) to solve - but I guess that makes sense when you consider that people's minds do work so differently.
The good news is that I have introduced my brother Greg to them and he is now thoroughly addicted too.
Update: When I checked the Palmgear site this morning (1 September - welcome to Spring), there were not one but two Sudoku programs in the 10 Best Sellers! I guess the craze is catching on (which reminds me, there's supposed to be a free Sudoku puzzle book in one of the morning papers this week.)