Be safe and avoid the games and applications that some are tempted to use. I hope I don’t offend anyone, but I do not accept any applications unless I have gone to a web site which links to Facebook for some practical purpose, like Ping.fm.
It would be nice if no one ever got angry or said anything cross, but Facebook doesn’t believe in that. Your profile is subject to being hacked, especially if you use the applications that mine for data, and your account can be suspended no many how many thousands of friends you have (the maximum is 5,000) if you annoy even one person. While I don’t feel like I’ll ever catch up, I endeavor to establish contact with people with their real email address and put them in my personal address book. There are some programs that help you synchronize this, but Facebook is not going to help you if they arbitrarily delete your account and you don’t have everyone backed up. I also have a very customized setup in Outlook, so I don’t want them removing or replacing the data that I placed in certain fields with what someone may have put in their profiles, because sometimes people don’t put their primary email address as the one in their profile.
I do feel that it is ridiculous to have a profile if you are not going to share your email address. There is adequate protection from email mining with the graphical representation of your email address in your profile, so only a real person can glean your address. Those people who often seem the most worried about their accounts are the ones who have AOL addresses, which I hardly consider to be email.
Even more importantly, I always stress to people, is not to use Facebook as email. It is NOT email. Email allows you to contact any other domain. There is no way to do that with Facebook and Facebook is not the only game in town, nor will it ever be. I often have to send real emails to people begging them to please just contact me directly.