Kaffir lime: Our weekend fruit identification challenge

We found one of these under a tree behind the unit we stayed in at our church weekend away. There were heaps of them so we didn't think anyone would mind too much if we picked up one to bring home with us (is it bad to confess that we stole a piece of fruit while we were on church camp??). When we found it, we knew it was some kind of citrus fruit but we'd never seen a wrinkly citrus fruit before. They look a bit like the surface of a brain.


Google images is very helpful when it comes to identifying unknown fruits. So now we know it's a kaffir lime.

I've only ever used kaffir lime leaves in Thai cooking until now. Does anyone know what you can do with the fruit part? Would you just use it like a regular lime?

I also have three bunches of rhubarb (locally grown, we bought it from a roadside fruit shop on the way home yesterday) to use up. I know how to do poached/stewed rhubarb and can do an apple and rhubarb crumble. I'd welcome any suggestions on what other things I could do with it....