I dont know of an existing mod to create a second page, but vBulletin has a similar feature built in.
Go to your Admin Control Panel and select User Profile Fields > add new user profile field
Once you are done, members can edit the fields by UserCp -- > Edit Profile, and they can be viewed in the profile.
For an example of what it looks like -
http://www.nnv2.com/forums/member.php?u=2860