If you're looking for an unusual hotel, this is my all-time favourite. I've stayed here and it's mental. Check out the different rooms:
http://www.propeller-island.de/rooms...l/11/index.php
Only issue is, of course, not in the UK.
For a day trip, the New Forest area isn't bad - some good roads to the coast and some decent boutique hotels in the area. I like this:
http://www.mrandmrssmith.com/luxury-hotels/the-pig