The internet doesn't care one whit where
you connect from.
I learned the hard way that it's much, much easier to use a web-based email address (Gmail, Hotmail, Yahoo, +a million other choices) rather than an ISP related one (e.g. Comcast). Because now you have to notify EVERYONE of the change if you want them to be able to get a hold of you Via email. And friends aren't always so good about keeping their address books updated. ;)
There is an option here - and on most sites that you sign into - under User CP
, that allows you to change the email address associated with your login ID.