Having a brief look through the community forums I have seen this mentioned a couple of times but think it would be a great idea to implement. Having the ability to group projects on the "All Categories" page. We currently have categories set to "support", "agile" or "fixed price" we cannot then group these further. Having the ability to group by client would be extremely useful.
We've implemented a slight work around by prefixing the project name with the clients name but having a real solution would be great.