I'm using mytags when looking for questions (as suggested by Jorge Castro). This list is sorted by votes. So new questions are hard to find. I'd like to have some RSS feed which contains new questions for my tags. Is there some feature at AskUbuntu? If no, can I sort the list by date?
There are several ways to accomplish this. First, every tag has it's own RSS feed near the bottom of that tag's page:
That will lead you too an RSS page for your favorite RSS reader (in other news, R.I.P Google Reader, we miss you)
You can also subscribe to email updates from tags as well.
Another newerish feature allows you to get a custom question list with just questions that have your favorite tags. To access it click "edit" (next to your favorite tags)
Then choose "advanced tag subscriptions".
From here you can create a filter for your favorite tags and have it emailed to you on a scheduled basis.