thanks samboll for the links, and sorry for this late response - i got caught up in some coding - i am back to WordPress now
I understand that the link you provided allows a user to switch themes - but my problem is a bit more complex. Here is the description
I am trying to develop a website say something like a university website not a blog.
I am the admin of a WordPress installation and i am creating users 1 and 2
I have set a theme and when 1 and 2 log in they can see the theme set by me - and they can change themes by using the plugin u gave me.
Now lets say that the theme the admin(me) set has a header image = cat for all pages.
User 1 wants to only change the header image to dog
User 2 also wants to change only the header image to sheep.
Also the theme set by the admin has a sidebar with link1, link2, link3
When ever a new user is created, they will get these links by default
User 1 wants to add his own link link 4 and create his own page and link his new link to his page
The way i thought of doing it was to give a page for each user where he can do all this(create link, create page, create content) - take all this in a form and create a page for them and add it to their individual pages
I wanted to know if I will have to code all this or does wordpress already allow such stuff
If my problem description is unclear - please let me know
Thanks a lot