LinkedIn is the best for business though, although others are trying to catch up.
Plaxo is trying to catch them, but they got caught spamming a while ago... they don't do it anymore, but still...
Plaxo was good for a few things... you could always have a backup for your Outlook Contact list if you integrated it with Plaxo. I had a friend whose computer died and he lost ALL of his contacts... thanks to Plaxo, he was able to get them all back.
Plaxo would also give you full contact information for people who emailed you. Their database was not searchable though.
Smart IT people knew that if you could send yourself an email from that person, you could get their phone contacts and full PLaxo vCard if they were listed in Plaxo...
So a headhunter could, for example, send himself an email from the guessed email address of the bank President. If it's ther right one, Plaxo auto-updates the vCard and he can get the full contact info.
If you or anyone else wants to connect on LinkedIn, why not drop me a FReepmail and I’ll send an invite in return?
Quite a few of us are on LinkedIn already, and as the article says it is a great business network.