So a previous poster talked about the potential for a TV show to get crossdressing out in the mainstream. While well intended, I don't think we'll ever be accepted based on a show...although I wish it was that easy!
Instead, it's gonna happen one person at a time. So long as we are closeted and never talk to anyone about it, crossdressing will remain suspicious, weird and regulated to the closet and the butt of jokes. We're going to have to talk to people about it, and a mass media message won't work...in fact, it'll likely backfire.
So this means we get to stretch outside our comfort zone. I read Isha's post a while back about talking to a group of guys at a coffee shop, and how she likely changed their attitudes from fairly hostile to at least understanding. Those interactions will have to happen, or we'll continue being the butt of jokes forever.
I know that personally I've interacted with lots of people, mainly at Lane Bryant and Goodwill. They see me buying women's clothes, and I've stopped bothering to make excuses for it. What's funny is after the initial shock is over (all of 10 seconds) people tend to ask lots of questions, and they appreciate you answering them. Heck, I've found the women really enjoy being able to talk about the issues they have with clothing, and almost always the interaction is positive. I'd like to think that I've made it easier for the next crossdresser to not get harassed when she goes to buy clothes.
Now, I'm not a fool: not everyone can do this. I personally can't tell people at work because of my job. Sure, we can all say "Be completely open with everyone!", but I honestly think that is crap. You have to be careful, and not everyone can be open at all times. But I'd encourage you, WHEN you have those interactions (and you will, trust me), be a good representative of the crossdresser community. Many people think crossdressers are creeps, but when they talk to one that is normal, it challenges their assumptions and in many cases makes them think otherwise. Plus, now when someone makes a remark later, that person won't immediately laugh, and may even say "Well, actually I met a crossdresser and she wasn't like that..."
You counter a message with a message.
The current message is "Crossdressing men are weird, they aren't normal, and they're creeps."
Counter it with "I'm a crossdresser, I'm normal, I'm not a creep, in fact I'm a fairly decent citizen. I work a job like you, have a family, and care about the same things you do. In every way I'm like you, but I happen to enjoy dressing up in women's clothes. Are you going to sideline me because of that?"
I'm willing to bet that over time, the answer to the latter piece will frequently become "no."