A few years back, Magnus Enarsson and Jonas Ljung, two friends of mine, got together and started brainstorming for a web-based system to keep track of gigs and bookings.
Jonas is a full-time performer, and Magnus is a full-time programmer (and amateur magician). Both skilled in their respective fields - and the first version was quickly put into use by several "heavy-hitters" here in Sweden.
Based on what they've learned from the first version, they now have rewritten it from scratch, and it is now even better.
Try it out and see if it suits your needs and preferences. And let Magnus and Jonas know what you think (if any feature should be added or simplified etc. )