FreeCrosswordPuzzles.com.au was started in 2006, initially just offering an easy and a hard British/Australian style crossword a day. It was quickly expanded to have an easy and a hard cryptic crossword, and then a few months later an American style crossword was added (these are actually far harder to generate than the British/Australian versions).
A community aspect was added for a while, allowing comments at the bottom of every puzzles, but it never took off and was removed a few months later.
The site has been converted to a Facebook application, and crosswords can also be embedded in your own site if you wish.
As well as crossword, sudoku, kakuro and other puzzle games, I have also built a travel site
I Want That Flight which compares flight prices (focussd on Australia).