a) the process is often very different. You can’t be half asleep and add a skype friend and then a facebook friend using the same mental concepts.
b) your friend ‘categories’ are very different. you have to stop, and go oh, fuck it, “I just met her randomly”. I wonder if various “sliders” for different attributes would be better. Don’t have time now to get out my sociology brain cells, but these would be used to describe how much you socialise with them, how much you use them to network commercially, your respect for their skills, your respect for them as an individual, if you just think they’re hot and you’re horny tonight, et al.

Interesting you mention flickr. I’ve sometimes gone months without adding someone because I couldn’t find (and was too busy, or too distracted) to find the ‘add this person to my profile’ button. Flickr’s lack of defined page layout has disadvantages like this. I couldn’t look for the link, but I would rather spend my time doing something else.

I’d love to sit down and think through what I reckon a more ideal friending process is, and one that can be versatile to use across the various networks. Maybe on my next long distance flight

Opening another can of worms, I don’t think I ever review my “friendlyness” with someone, despite this certainly changing over time. I’d suggest, through social network portability, that your aggregate interaction could help build up/reduce your “closeness”. That is to say, the people on your network who have viewed the most flickr photos, commented on them, sent you emails, have LinkedIn contacts in common, et al… then get used. Its important that it is two way. I’m sure everyone wants to be on Mark Zuckerberg’s contact list, and would happily nag him on flickr, twitter ad nausem, but it only when he reciprocates that the connection is strong.

As an example, I have the following lists: Viddler team, friends, family, Users, Companies. This way I’m able to separate each person accordingly.