Users can now have custom css if you use this with another module

You have a great module here but combined with another great module by Davy Van Den Bremt, the User Profile Theme module at http://drupal.org/project/user_profile_theme it would be a match made in heaven (at least I hope it works fine, I have not tested this extensively)

First, edit the current release (5.x-1.x-dev as of writing) to resolve the bug http://drupal.org/node/211212 and you can optionally remove the part where the css file is added on view at around line 155, I say optional because it doesn't seem to add a duplicate css file even with the next few changes.

Now in that part of the file (line 155 of the user profile theme module) you copy this:

// We add the CSS file to the header.
		if(user_access('view theme') && user_access('have theme', $user)) {
			drupal_add_css(_user_profile_theme_get_filename($user->uid), 'module', 'screen');
		}

Add just before the break in case comment, case node and case shoutbook of the function blog_theme_menu() in the Blog Theme module:

if (module_exists('user_profile_theme')) {
		// We add the CSS file to the header.
		if(user_access('view theme') && user_access('have theme', $user)) {
			drupal_add_css(_user_profile_theme_get_filename($user->uid), 'module', 'screen');
		}
	  }

***** I do not know case image is for which display so I did not add it in, anyone can enlighten me on this as I can't seem to find the page which uses that case *****

Next, remember to add

if (module_exists('user_profile_theme')) {
  	global $user;
  }

just below the global $custom_theme; line in the same function and you should be all set for users to input their own css.

Set the appropriate permissions for both modules and you should see a css option in the user account edit page.