The problem with Wolfram Alpha is this: it's awesome when a query works, but often it either doesn't understand your query on the first try, or it just doesn't have the data or computation you're after.

Siri has the same UI problem. You either have to read through the list of commands and memorize a few, or you have to deal with the constant frustration of trying something three times before giving up and doing it manually.

That said, these UIs are fun for a coder. :-) It'd be cool if somebody were to track and curate interesting Wolfram Alpha queries in a blog/tumblr/subreddit. The closest thing I could find was this:

http://www.makeuseof.com/tag/10-search-terms-put-wolfram-alp...