Need ability to capture user defined alpha-numeric input at sign-up

Hello, me again.

I'd like to capture a couple of more items at sign-up is this possible?

Is it possible to alter the 'Blogs Type' plugin in such a way that I have one select box and one text entry field, the value of which gets written to the database?

If yes, I'd appreciate very much you showing me how to do this.

Secondly, is it possible to include more fields during the sign up process. I'd also like to get peoples addresses and telephone numbers.

I'm thinking of using gravity forms somewhere to augment my sign up process yet it would be nice all of the above was written into the user table.

Many thanks in advance.

Ralf