Mobile technology has so far mostly been confined to the client side, for fairly obvious reasons - traditionally, clients are mobile, and servers are not. However, not only is hardware getting smaller, servers are too. When your application server can run on pocket-sized £25 hardware it opens up some pretty cool possibilities - your server is literally lightweight. Not only can you have location-based services, you can have locatable servers. Servers can run on phones, they can run on the Raspberry Pi, and so they can go almost anywhere you can think of. Modularity gives software the flexibility it needs to cram into these tight spaces without sacrificing power. This talk will demonstrate developing and deploying a web application to an application server embedded in a silly hat.