<<It's actually a binary (one-argument, infix) method, like +, =, or ==; it's the - and > characters put together rather than being a specialized glyph like the left arrow was. It creates an Association, which is a key-value pair used in things like Dictionaries.
If I remember correctly, any characters which can be used for binary methods can be strung together to make other binary methods - sometimes you'll see these turn up in specialized contexts. For example, there's also ==>, on Booleans, for implication ("a implies b").
Ben Schroeder>>
Thanks Ben, that makes a lot of sense. It's similar to how 1 @ 2 will return a point. And, of course, after reading your answer I realised that what I should have done is used the method finder to look up ->. I just haven't quite got it into my head that there are only objects and messages, and therefore if something isn't an object, it has to be a message! :-)
Cheers AB