Are you a fan of Kakuro Puzzles? Or, you might know them best as Cross Sums.
I'm pulling together a collection of the puzzles that I've created (well, I've created the machinery that has, in turn, created the puzzles). A sample is HERE.
There's a range of puzzle sizes and densities (more black squares means the puzzle's typically easier).
If you like these sorts of puzzles, I'd appreciate any comments you have on them.