Earlier on this week I was working with a client who had gathered a load of email addresses from potential customers via an online competition. The client wanted to know the Twitter accounts of the people that had entered to see if there were any influential users in amongst the list - the only catch was that they only had their email addresses. I spent about 20 minutes searching online to try and find out if you could search for Twitter users by their email address and had no luck. Unless you're using the API, there was no simple way to do it (so I thought). After playing around with a few different methods I finally managed to do it, so I thought I'd share my method with you all in case you come up with the same problem!