For those of us without the luxury of their own domain, or who are worried that someone might be able to easily guess their myspace@alicejones.net addressing scheme, a few e-mail masquerading services are available. My favorite is Sneakemail.com, which lets you create an unlimited number of e-mail aliases for a modest $2 per month. This way, you can use one unique e-mail per Web site, and all the messages get forwarded to your "real" mailbox. The service even handles replies, so that the Web site never has your real addressrunning patches for all browsers, adobe, os etc etc.
The risk of malicious software from P2P (peer to peer) networks far outweighs any legitimate need for BitTorrent or KaZaa. On your personal computer, I still don't advise its use, but I can understand that there are several legitimate reasons for using it. Use reputable Web sites to obtain shareware applications.
If you must participate in P2P, use a separate, nonadministrator user account for those functions. Never run software that you download from a P2P network in your administrator account, and always scan these downloads with several antivirus packages. Virustotal.com is a good place to do a quick scan of a dubious download if you don't already have a solid security package such as Norton Internet Security 2010. If you're a tech-savvy power user, run P2P software in a virtual machine to insulate your host operating system.