Anna: Here it is! The project I wrote about here is now done. It's a very simple bag, large enough to hold a cell phone or PDA, a few cards and some cash. Not large enough for my set of keys, though, but I don't like to carry those in my purse anyways.
I'd originally intended to have only one button in the flap's centre, but as I worked it, I found the corners curled quite a lot, so I made two button holes in the flap, instead. It still curls a bit, but it's not as much of an issue. The bag itself is all one piece, reduced in width slightly for the flap, then folded and crocheted closed on the sides. The strap is made long enough to be worn across the chest, rather than on one shoulder. I find those are forever slipping off my shoulders.
I think it worked out rather well. :-)