I just counted the emails I had over Christmas asking me to contribute to various titles... six altogether. I'm flattered by every one of them, and it's difficult to say no when someone asks (but I generally do). From now on I will not be contributing to any other projects until Rainbow Orchid is finished, it has to be my priority. The one I enjoyed most, recently, was the two page girls' football strip in Paul Scott's Sunny For Girls, only two pages and a last-minute decision. Fun.
A few years ago I played Pirelli in Sondheim's Sweeney Todd, which was great fun. Below is the poster I designed and drew for the production (my own original design, which has been copied once or twice, the risk of putting your work on t'internet), and more on the real Sweeney here.