Hmmm, assuming since you posted an Ask HN that you read HN comments, it's difficult to believe you haven't seen lots of people talking about the usual subjects (at the moment) - node.js (javascript is the language), clojure, haskell, OCaml, scala, erlang. All of these will give you a new perspective coming from the three you mention, the first two are probably the most web-focused (though perhaps people will disagree with that?). Also, plus one for smalltalk/seaside, and minus one for python, which isn't mind-bending enough coming from Ruby in my opinion.
Comments
Hmmm, assuming since you posted an Ask HN that you read HN comments, it's difficult to believe you haven't seen lots of people talking about the usual subjects (at the moment) - node.js (javascript is the language), clojure, haskell, OCaml, scala, erlang. All of these will give you a new perspective coming from the three you mention, the first two are probably the most web-focused (though perhaps people will disagree with that?). Also, plus one for smalltalk/seaside, and minus one for python, which isn't mind-bending enough coming from Ruby in my opinion.