understands

.NET, C#, VB.NET, F#, JavaScript/Node.js, HTML, CSS some HTTP specs and a bit of everything under the sun (C, Python, Ruby, RegEx, Parsers/Compilers, etc.)

will never understand

Java

can pitch in with

Bugfix or enhancements provided that your code is readable (e.g. have a consistent coding convention) and I understand the basics of the platform you're using.

currently studying

Lots and lots of functional programming. (Monads, CPS etc.) Functional+OO seems to be the new hotness for languages these days.

can mentor in

All things .NET - C#, Mono, F#, VB.NET, CLR, CIL, WPF, Silverlight you name it. I also dabble in the *nix world with Node.js and other server-side javascript technologies as well.