I have been testing the AD7746 capacitive sensor over the weekend. While it works fine for touch sensing, it's limited to 21pF of capacitance which won't do for my current project. Anybody interested in buying the board for $20 (incl. S&H) ? Send me a PM.
I'm curious as to how the max of 21pF capacitance turns out to be a limitation in practice. Do you need a particularly large touch plate or something? Can't you hack it with an added series cap or something?