Where the heck can I get one? I can't always pull my phone out when I'm in a meeting and being able to reply to a text via my watch (without talking) would be awesome.
Also check out the coffee app, which let's you reply from an extensive list of canned responses.
The watch ui requires rethinking of inputs (like coffee app) or if someone makes a gesture based 'keyboard' (but generally a traditional keyboard may not work well on a watch).
Also Google Microsoft beta android wear keyboard.. There was a news story about that a few months ago..
Post back please what you do so others can follow what you learn!
Google has decided to do away with keyboards in favour of 'google now' but there are situations where one may not want to show their 'status' by declaring to their watch "ok google, yes im special". For occassions like this a keyboard was developed in an app called "flickkey" (which works brilliantly with a tiny bit of practice) but it was rejected by google due to their ios like policy of rejecting third party os system being intergrated into their own.