Very similar to other questions I have knocked my external drive and it makes clicking and wee whirly noises but computer doesn't recognise it, anyone got any ideas. Who can you recommend to retrieve data as it has ALOT of irreplaceable photos on it.

A Mull, September 2011

Addendum:

Whatever you use to recover your data, you MUST copy it to some other drive.
Your drive is physicaly damaged and it's functioning is totaly unreliable.

Have the destination drive connected and ready BEFORE you attempt anything!
The new drive should have a larger capacity as you may need to extract a raw image of the drive content. That raw image WILL be larger than the actual capacity of the drive due to the overhead and information chunks parts.
Count AT LEAST +50% capacity.

Electro, October 2011

The sounds you briefly describe realy don't sound good, like the heads got disaligned or something similar.

You may try the SpinRight application.
There are a few others similar ones available over the web.
ALL reliable ones will cost you some amount.

It's also possible that some contact was broken in the fall, but it's not probable.

I can't recomend a specific place, but some data recovery lab may be able to recover your photos, but it will cost a LOT!

Electro, September 2011