Have you seen Yahoo Pipes? It’s an incredibly easy way to stitch together pieces and parts of many different websites and services.
Pipes is based on Unix pipes, which allow the creation of small, focused scripts and programs that do one thing well, avoiding bloated everything-and-the-kitchen-sick applications (look at the menu in MS Word for the definition of feature bloat.)
I’ve been playing around with a module that scrapes search results from GoogleBase Personals, which is even easier than earlier attempts at creating dating site mashups. I spent about five minutes on it, and the results are overwhelmingly HotorNot for now because I haven’t added any filters. More documentation on the system will be available in a few days, at which time I may refine the Pipe.
I’ll probably try a Yahoo/Match or OKCupid/PlentyofFish mashup at some point if someone doesn’t beat me to it, (hint, hint). Be sure to link to your dating site Pipes in the comments.