Hopefully you're enjoying Flock now. If you already had accounts on Facebook, Flickr, YouTube, Twitter, and/or del.icio.us, you've seen how amazingly easy it is to integrate those tools so that your friends updates just pop up automagically in the "People" sidebar (you can also update your Twitter/Facebook status, and check to see if you have any special notifications from these sites at the same time!). If you write for or have a blog, did you check out the feather-pen button which lets you set up multiple blogs so that you can submit stories straight from your browser? The Web Clipboard is the tool that got me to switch from Firefox to Flock (they're based off the same code, Flock just has some optimizations for web 2.0 tools). The Clipboard lets you drag and drop web images from sites to blogs to emails and more. Mac users may be less impressed with a lot of these tools, as Mac does a better job at integrating these tools already, but Windows users may need to make sure they're not drooling into their keyboards to much.
Did you notice the inline spellchecking? The ability to surf using tabbed browsing? And don't forget, you can also use addons that expand your power - sort tables inside your browser, block *all* advertisements, and more. I created a list of great firefox / flock extensions you can start with.
Do your part - use the flock buttons to promote Flock and tell your friends about it!