Pictures are mostly not useful to me, at least in terms of being able to use them for later recognition of people and/or for connection maintanance. They are too flat, and have too few forms of input. No one has a face in my dreams, my mental pictures, or my memories. At most, they might have a piece of a face, if my attention was on something specific for long enough. This probably relates somehow to my utter lack of ability to describe people's physical appearance (I'm doing well if I can describe hair color, eye color, or long, short, curlyness of hair).
I tend to have trouble recognizing people out of context, more so if I don't see much of them even _in_ context. Voices help, though. My voice/ways-a-person-moves recognition works much better than my face recognition, but they both require a fair amount of interaction with a person before they are useful.
It's very difficult for me to remember meeting someone for whom I have no previous information in my head. Even if there was enough interaction for then to catch my attention, this is true.
People's visual appearance tends to startle me repeatedly until I get used to what they actually look like, if I have a sense of them which was not developed at the same time as learning what they look like (ie, people I interact with more online than in-person). This can be very annoying, but repeated exposure does seem to eventually get me to remember what someone looks like so I can stop being startled by it. Voices tend not to have this problem. I'm not at all sure if sufficient time between seeing a person might reverse my ability to recognize them, however.
Names that I've never seen written are _very_ difficult for me to remember. If they are written, the likelyhood of me remembering them increases _dramatically_. This is probably why I remember people's login names and IRC names and LJ names better than their offline names.
With all of this, I have no idea how I know and have a decent chance of recognizing and recalling the names of as many people as I do! *shakes head* Hey, at least all of the above is mild, and isn't _always_ true. I mean, I tend to recognize and remember the names of my family and close friends (I'd even go so far as to say I don't remember ever having had trouble with family for faces, but sometimes their names still slip my mind). :)
So, yeah. Don't assume I'll recognize you, even if I know you. More so, don't assume I'll remember your names - there is a reason I so rarely use names! And don't assume I'll know/remember you if you've only met me a few times. Finally, if you've never met me, but you think I've seen your picture, I'm unlikely to recognize you.
I think this all is being posted as a result of reading the
faceblind community a bit, although I don't think I'm faceblind, based on what I understand the definition to be.
[edit: Or, if I _am_ faceblind, it's mild. Reading the online book about it makes me less sure I'm not.]