I wish Twitter had higher performance and uptime. It is often sluggish and even Twhirl has to stopping accessing it for 5 minutes, or longer, at a time to allow it to catch up. I continue to find incredible people and publishers to follow including: Leo Laporte, John C. Dvorak, PC Magazine, New York Times, etc.... So, I am finding more value in the service every day. I just hope they can make it work better and figure out a way to make money on it, because without revenue, investment will eventually dwindle.
I have been using friendfeed a lot more lately. I finally figured out the value and have been linking my favorite services to my friendfeed profile. Like NetVibes is for my blog and publisher feeds, I like the way friendfeed has become an aggregation point for my favorite social media feeds. It also performs very well.
Finally, I have been using Digg more and more. I am finding some great articles on the internet and when I am reading some of my favorite magazines and news sources. I like that I can keep track of these articles on Digg, see what others are finding valuable or interesting, and go back to find articles I want to forward to others.