Similarly, I get regularly get link requests on various social-network-featured sites from people who I can't figure out who they are, because they're too cutesy about their online handles and "fluid identity". I likewise tend to ignore such link requests. (This doesn't count spammer fake identities, like the ones who infest MySpace. Those are easy to recognize and dismiss.)
If someone wants me to recognize / approve / backlink / also friend / whatever the link requests sent to me, don't use an impenetrable or annoying fluid identity. Put your name and your face behind you words.
I use the "fallenpegasus" handle nearly everywhere online, mainly because it's almost unique. But, whenever possible, I also put my actual real name, my photo, and links back to my main online presences, just to avoid causing that annoyance in other people.
If you use "spam" as an excuse, that's a lame excuse. If you are Joe User, the big web mail services have excellent spam filtering. If you are running your own mail server, turn on all the strict antispam tools in your MTA, and enable greylist and blacklist filtering.
If "stalking" is your fear, well, while that is a valid problem, especially for attractive women and for people who have some measure of celebrity, I'm not saying to publish your physical address.
And on a similar note, even if you have a good linkage between your online existence and your realspace one, I still need to know who you are in relation to me, and why I care. Unless you are confident that I know your name on sight (and I have to meet you about 4 times before that starts to happen), some "how do I know you" is necessary.
It can be as simple as "we met at last night's geek event, and spent a couple of minutes talking about frobnitz" or "I saw your profile on othersite", but I need something, or otherwise you are likely going to get, best case, an email saying "and just who are you again?".
A couple of months ago, Tim O'Reilly posted a plea about the same thing. I get a handful of "who is this?" link requests a month. He gets dozens per day.