The Disability charity Scope is running a campaign to make polling stations more accessible. They've got a great website where you can look up details for the polling station near you and also take part in a survey to report back.
Even though more and more people are registering for postal votes, accessibility at the actual polling stations is vital and although most local councils will review their locations on a regular basis this is really welcome as a campaign.
In Liverpool, as I discovered recently, we also involve an organisation that supports blind and partially sighted people in making the Presiding Officers (they're the people in charge at the actual polling stations) aware of the issues that would face someone coming in to vote who is blind or has sight problems. I am told we are the only authority to do this.