Worthy of note: Five key demographic features about the current online social-networking landscape.

This research is courtesy of Pipl, a specialized search engine claiming to focus on the “deep web” for better targeting of person-search queries. Part of that deep-dive involves datamining social networking profiles from Bebo, MySpace, Friendster, Facebook, Xanga, and Hi5. Hence the resultant research results.

One more note: It’s not crystal clear just when this was all compiled, which is crucial for context. It’s not even mentioned in the methodology. But if you look really, really closely at the graphs, you can discern a “December 2007″ timestamp; and a little digging confirms a November-December 2007 range.

So, without further ado, the five facts:

1. The Women Are Younger, The Men Are Older - The younger demographic is female-dominant while the older demographic is mostly male.

2. Bebo and Xanga Have the Youngest Crowd - Those two sites are heaviest on teens and young adults, with a marked drop-off in users 30 and older. The other four sites are also dominated by youngsters, but there’s a bit more balance.

3. MySpace Is Still the Largest, By Far - Not surprising, with 184.1 million active users. Supplementing that is an 81.5 percent year-over-year growth rate, also tops.

4. European, Asian and South American Members Are Getting Younger - In contrast to the U.S. user bases, which are actually trending slightly older.

5. More Women On MySpace, More Men On Hi5 - This is actually the current trending: More females are bolstering the ranks of MySpace, while Hi5’s growth consists of mostly males.