This instructable describes how I repaired mine.
Step 1: Materials
- Glue -- I used Ados F2 as it is flexible and the break does move under strain
- Heatshrink tube -- thin
- Cutting tool -- I used scissors
- Clamp or rubber bands
- Heat source -- to shrink the tube
Step 2: Heatshrink
Step 3: Repairing
Slide the heat shrink over the break and shrink it. This will help hold it all together.
I used a rubber band cut from a bike inner-tube because it was what I had to hand.
Leave it to cure and you're done!
If the clip doesn't have enough "spring" to hold the phone against the charging connectors properly use a rubber band wrapped around the mounting post and the clip to help (that's what I had the inner-tube band for!)
Oh and one more tip: to release your phone from the dock push it out from behind rather than push on the clip. Doing it this way puts less strain on it.