The trouble with "Rowan" is that it's a pretty common name. OK, not as common as "Mary" or "Chris" (when, in a fit of thoughtlessness, I applied to FurryMUCK for a new character named "Chris", I received a note back stating, "Chris is taken. So is Kris, Chrys, Khryss, Kriss, Chriss and Riss. Please don't ask for any variant on this name, we have enough." I came back with a request for "Xylantha."), but still, as handles go, it's pretty common. Since it's also a type of tree, a Google search on it yields nearly a million results. "Rowyn" is better by a few orders of magnitude, but it still yields over a thousand. Presumably, some of those are me, but I didn't find them in the first several pages.
Rowan is still a big improvement over my very first computer handle, which was "Cat." That no one else was using that in my university's computing community tells you something about the size of the community.
My own RL name (combined first and last) is much more unusual -- in fact, almost all the results from it are about me. If I throw in my middle name, I don't get any results at all. Unique!
But a good internet handle, to me, is still one without spaces. URLs don't have spaces, and I dislike using underscores, or dashes, or concatanating names. I'd rather have just one word in a name.
So I'm sitting here thinking, "Do I want a unique name?"
The trouble with unique names is that they have to be either made up ("Hi! I'm Fyiara!") or combinations of two or more real words/names. I don't want to do the first/last name route for the "no spaces" reason cited above. Sometimes two combined real words sound nice to me. I've used handles like those a few times in the past: I had FurryMUCK characters named "GhostDancer" and "Shadowsteel."
But combined-word names aren't necessarily unique--the two above yield hundreds of hits, none of which have anything to do with me. In fact, even "Xylantha" isn't as unique as I thought it was. Lycos and Geocities both have people who use it as a handle. The only name I ever used on Furry that gets no hits from Google is "Keth'avith."
Furthermore, combined-word names suffer from what I believe RHJunior once termed the "Backlot Holloywood Indian" effect. They can come off as hokey or pretensious.
And all of this aside: Is it just too late? I've been going by Rowan for most of a decade now. Who's gonna call me "Stormcipher" if I change my mind now?