Yes, I'm writing in Ron Paul. Votes are NOT discarded where they are not counted for a specific candidate, however, they are tracked as 'none of the above' 'undervote' everywhere. If you would rather vote for someone on the ballot than count as one of the none of the above vote, that is one thing, but to say they are simply discarded isn't correct, even when they don't tally them up for 'Ron Paul'.
I would write him in even if we can't make him an official write in candidate, and I'm pretty confident we will complete that process, in CA. Because for me a vote for none of the above, while taking the trouble to vote so they can't spin it as apathy, better says how I feel than a vote for any of the candidates I DON'T want, who are on the ballot.
Also, one of our people who can edit wiki should edit this to say Ron is already an official write in candidate in Maine, and the process is underway in CA and likely other states, and that he can be written in in states that allow write ins, generally.
http://en.wikipedia.org/wiki/United_States_third_party_and_independent_presidential_candidates,_2012