As Jonathan mentioned, to do that with old routes you will need to hardcode a list of your controllers. Then anything what is not a controller is a username. But this is not the best way to do it. I like better the way the new router works, that is using predefined defaults.
So what you could do is having a number of user function in a user controller, eg. /user/create, /user/update, /user/delete and set one of this functions as your application default, e.g. /user/show. Now, any request to /name for name not in controllers would be mapped to /user/show/name. Unless Jonathan will correct me here, as rather "name" would be used as function of the default controller, i.e. /user/name. But let's assume this will work fine, then for other functions you just use the user name as one of the arguments e.g. /settings/appearance.xml/bruno/1/?color=blue. An alternative option would be to use different subdomain for each user http://bruno.twitter.com/settings/appearance.json but I don't think this is supported in any way by new routes. A more complete solution to tackle this (and other examples I mentioned in the beta routes thread) could be something similar to $label replacement used in old routes. With this implemented, an example usage for Bruno's case would look like this: "/$user/$controller/$function/$args/$vars" -> "/$controller/$function/$args/$vars&client=$user" or "/$user/$controller/$function/$args" -> "/$controller/$function/$user/$args". How this should work? Each of the labels would simply match a regex of (.+) or maybe more limited ([\w.-]+) with exception of the last label (here $vars in example 1 and $args in example 2) which could contain also special characters [/+...@?=&;:,*!()']. Or maybe even to simplify things, everything between two "/" characters would be assigned to a label. Then the labels would be used to reorder parts of urls. After reorder is done the new router would deal with the string as if it was the original url. I assume all this is app-specific and domain and app parts are stripped before. Notice that this would be quite general and you could do with it things like: "/author/$name" -> "/books/author?name=$name" or even url shortening like: "/short-name" -> "/controller/func/arg1/arg2/arg3/arg4" Alternative option would be having named routes like Routes<http://routes.groovie.org/manual.html>does and instead of arbitrary label used specific ones for controller and function and treat the rest as query arguments of it, e.g: "/{user}/new/{controller}/{function}" will give "/c/f/user=smith" for "/smith/new/c/f" but I guess this is a bit too complex and not clearly better than the other method (although I like {label} notation better than $label). OK, so I leave you with these ideas. Maybe we could find a nice way of making the new routes a bit more flexible by discussing this further.
