Is there a list of available APIs for Bitcoin exchanges? So far I have seen some Perl modules; Finance:MtGox and Webservice:MtGox for interacting with Mt.Gox, a Ruby gem for Mt.Gox and a Python based command line client for again, Mt.Gox.

I'm wondering if there are any other language APIs for other exchanges? 

I'd especially like to find a Java API for more than one exchange.
There is now the XChange library

This is a pure Java library that has been released under the MIT license. It currently supports Mt Gox, but there are simple hooks to allow other exchanges such as Intersango and CryptoXChange to be supported.

It is currently used by the MultiBit client.