Fixed-rate fud - what to do?

Hibbo

Hello everyone, I'm after a wee bit of advice.

My current situation is;
Bought a flat for £57k just over three years ago,
Remortgaged one year ago to a 10 year term, fixed for the full ten years at 5.68%, monthly payments £492.
Early repayment fee of approx £1350
I am a higher rate tax-payer,
£17k in an INGdirect (ex Kaupthing edge) savings account, £3600 in an ISA and £4k of Premium bonds.

My savings were to be put towards buying a house, keeping the flat to rent out. So now the big question, should I take the hit with the early repayment fee, blast my savings in to the mortgage and put the remainder on a short-term tracker and pay it off quickly (with the money I would have been putting in to my savings each month).

The way I look at it my savings won't be earning much interest, and what I do get I'm taxed at 40% on (save for the ISA of course), so maybe I should rid myself of the mortgage whilst rates are low and then start again on the savings.
On the other hand, it's nice to have the money sat there so I can make a move if I find a house I fancy, although it will probably be in a few years.

Thanks is advance for any advice!

Hibbo

Erm, have I posted in the wrong section?

Is there a guide I should've read before asking this question?