First of all, the http:// it's optional. my username is just alcides.ideias3.com

Everyone now can have a blog (blogger, wordpress.com, etc..) so It's not hard to get an website running. Even domains are cheap (you can get around $6), so you can have your own personal page/blog with $6 and with myname.com/.net/.org

For me it makes sense alcides.ideias3.com since ideias3 is my workgroup. user@provider.com will resemble more with email, and since people are scared by SPAM, maybe the domain (or subdomain) would work better. And it's easy for me to set up one :)

Hope I answered your question.