I wish there were a way to create custom data structures without casting to and from interface{} all the time. Heck, it would already help if there were a shorthand for interface{}, like "any" or something.
The usual pattern is to use a type that requires the thing you pass in to have methods that you use for the data structure, like sort.Interface[1]. It's faster, safer, and better than using interface{}.
As for shorthand, behold!
[1]: http://golang.org/pkg/sort/#Interface