Hi - I wanted to let folks know about something I came across recently, and have just ordered. I haven't received or tested yet, so I'll have to get back to you about whether it actually works, but I haven't seen it posted here before (hopefully that's not because it doesn't work).
GRISK (GRI) makes a variety of environmental probes, and in particular, has two self contained modules for water detection - the WS-20 and the 2826FS. They both work with included remote probes for water detection. The primary difference is that the 2826FS is designed specifically to work with a wireless transmitter whereas the WS-20 is self-contained and includes an internal alarm, ability to reset locally, etc. However, both use internal batteries, and both have terminals for both N/C and N/O sending devices - so you should be able to use with a DS10A or a Powerflash module. Both units are around $30 (I ordered from Spytown).
For those who don't have the time for mods like the recently posted one (which was very impressive), these look like a very inexpensive, low effort way to get a flood detector feed into an X10 system. They are less expensive than the CR2 probe that smarthome sells, and seem to be much more flexible. For instance, both of these can take multiple additional probes which are available very inexpensively.
Let you all know how it works when I get it set up.
Michael