Yeah, totally agree - personals have their function, for sure, and suit some people, but I like the idea of a social group who happen to have poly in common, to get to know people as "just" people, rather than looking at them (or them looking at me) as a potential date or not. It creates a very different dynamic.
In terms of poly personals, a lot of people like OKCupid.Com for a free poly-friendly (i.e. you can set your relationship status to "available") site.
"Listen, or your tongue will make you deaf." - Native American Proverb