It's a busy Thursday, but I've got a couple of minutes so I'm going to tell you about a few web-based services I use on a daily basis. All of these can be used for free.
I'm going to skip services like Twitter, Facebook, YouTube or Linked In and stick with more SaaS-type services.
I manage several websites, and track metrics for each of them. Google opened up GA to the public in the summer of 2006 and now I'm wondering how I ever survived without it. I used to pay actual money for sites that did a worse job than GA and GA is complete free.
If you manage web sites, or even a single site, you've got to implement GA.
Flickr is the only site I pay for that is strictly for personal use. I host all my photos on Flickr, and even a bunch of videos. Flickr is free but you're limited, so power users will want to get the pro version. It's worth it.
On Twitter, I use shortened URLs, due to the 140 character tweet limit. bit.ly enables me to track click-thrus via Twitter. I can see which tweets get the most traction and which go viral. Conversely, you learn pretty quickly which tweets nobody gives a shit about.
Instant messaging is the new email. Haven't you heard? I use meebo.com to do all my instant messaging in the browser. You simultaneously login to Yahoo!, Gchat, MSN, Facebook and more.