If you are a power Outlook user, there is still no SaaS/online substitute for what you do.
But, Facebook's recent feature add of "Lists" is the closest thing I've seen to the 'Categories" feature that is so critical to my relationship management strategy.
For example, in an effort to add value to my network, I might send email to everyone in the "Tech Lovers" category when I find something that is interesting (I think for them).
In Facebook, until now, there wasn't a way to segregate people by your perceptions of their interests.
Now, you can.
Plus, Facebook alleviates for you one of the biggest challenges of Outlook...keeping the contact data up to date (since that is offloaded to the other individual-something that Plaxo, among others pioneered).
So, this is a big challenge to Outlook (and hence Office as email is still the killer app, no? 🙂
It's still not easy enough from a speed perspective compared to Outlook, I should add, but it is a hint of things to come.
Once Facebook starts empowering users to view their contacts in a myriad of ways (geography, relationship, interests [as tagged by user], etc.) it becomes a true (and robust) Personal Information Management platform.
I have a few ideas about what MS could do, but you first. 🙂
I'll save mine for a later post.