Hacking and password security and all that kind of junk has been all up in the news lately, and this Dropbox breach is just the latest story I heard about today. This particular one was a breach that appears to have allowed a user to bypass the password and gain access using only the username for an account. That sucks, and maybe this kind of thing is preventable by adding another level of randomization. Everyone should know by now that you should be using random passwords and storing them with a tool like 1Password. Well using a password manager like this means you also don't really have to know the username either, so why not add another level of security, however small it might be? I'd like to do some more in depth research on this, and see if randomizing the username actually does increase security and by how much.
Even usernames that require an email address can have some randomization added to them. Just about any host should allow you to create an "email alias" that will forward to your regular email address, for example instead of firstname.lastname@example.org, set your login for facebook to use something like email@example.com.
I think this is something I'm going to start doing, but obviously it's not going to work for everything. Having a randomized twitter username, for example, would probably not be the best choice.