User alias possible?

The user's blog automatically picks up the username with which the account is created- for example, admin's blog when the username is admin- it even matches the letter case (upper/lower) of the user name, as no doubt it should.

I face a situation where I would have to add the names of non-profits with rather long names. So, I would like the usernames to be shorter (otherwise, they would have a tough time logging in with names like Ability Foundation), but, with an alias, give a more professional look to the blog name etc.

I know the mailalias does something similar for email addresses, but, ss this possible for usernames?