Should you register an account everywhere online?

My thought today is should you register an account on all the major websites as soon as they start to become useful?

How you tell this is just a matter of listening to what people are talking about or if you see a site you may in some way use. Even if you have no plan to at the time. This is because you need to get in early to be able to get the username and often url that you want. Most people, like me want the same username accross all community sites. This is because you want to remember it but also so that seo and other people can find them. I never want to have the name+random number option but some people like my brother have adopted that style as the default as his name is too common. chrisbailey79 or baileyboy79 allows him to have a year and get his name. My name is not so common so I can get mine mostly but a new problem was recently highlighted to me, i think in boagworld or .net podcast, namly takeovers. Google and yahoo buying companies they take on the user system and add it to their own in a dual manor and sometimes require it too be the same name.

Some people who paid for Flickr accounts then had to create Yahoo accounts if they did not have them, and Yahoo being slightly big can be almost harder than hard to find a real name you can use. Their account would not work if they could not create the account, and this is a service they paid for.

Also a point for the future is if the good services online are run by Google, Yahoo, MSN etc... and the usable names are used up in less than 10 years what will happen if my son wants an account in another 10 years? Two things may happen, more domains, like google and some service providers have, so my username is tristanbailey then @gmail.com because I registered early but other friends have arksports then @googlemail.com and we just have this second part as a choice not free entry. It is like namespaces for usernames I guess. Or the systems will have to be broken up into pieces or run a bit like keychains on my Mac, having lots of usernames (probably auto assigned) assigned to one username and password. Both these do not really solve the problem for one website.

I'd be interested in any other ideas, to solve it. I figure I will have to make a system work for a site I work on at some point.