programming puzzles?

[John Salerno]

Similar to the Python Challenge, does anyone know of any other websites 
or books that have programming puzzles to solve? I found a book called 
"Puzzles for Hackers", but it seems like it might be a little advanced 
for me, and I've also read that it focuses too much on encryption and 
security issues and doesn't really have coding problems, exactly. But 
something like that book would be fun to have.