I've been a user of the Anquet products for a wee while now and they've just sent out a wee email saying that they're releasing iPhone and Mac versions….
IPHONE AND MAC BETA TESTERS REQUIRED
Very soon, we will launch our new Apple iPhone and Apple Macintosh versions of Anquet.
We are of course very excited about this development, bringing the ease of Anquet and access to Ordnance Survey and other maps to these excellent platforms. You can view some screenshots on our website.
Our new iPhone and Apple Macintosh products are currently going through final internal testing, and we now wish to extend our testing to some external beta testers. If you would be interested in helping out then please see the details of our Anquet Maps Apple Beta Test Program.
More details (incl screenshots) here