It's still very much an idea atm. Basically it involves a room with magazine images glued to the walls in a certain way (it would be far more interesting, but I don't want to give the idea away).
I'm in the Midlands, so there's Birmingham and Walsall art galleries...
if you can find a local shop front which has been empty for a reasonable amount of time approach your council and ask if you could use the space as often shop front owners are obliged to allow sellers in to use the space if it is temporarily empty. Im not sure if it applies to small exhibitions especially if you are physically sticking stuff to the walls but is worth an investigation.
if your near Birmingham, near the city centre there are several disused buildings waiting to be demolished (fazely street and curzon street) which you may be able to ask permission to exhibit in if they are in ok condition. They are a good distance between the main city and millennium point and you could leaflet around the other art galleries ....
or alternatively the Ikon gallery may be of some help