ooh yeah, this thread is turning into some good ol' fashioned feminist bashing!
Now, for my two-cents.
Yes, holding open a door for a woman or standing on a bus so that a woman can have your seat does have it's roots in chauvinistic behaviour. Most men though, have been trained to do this through years and years of practice and they are not trying to subconsciously put a woman down because of it.
Next thing you know I'll be accused of being ageist for helping an old person across the street.
The thing is from a male perspective, there's nothing worse than being overtly chided for doing what you think in your mind is the right thing to do. If we are to have equilibrium on gender power relations there's a very simple solution.
Girls: When a man offers you his seat, instead of berating him for his chauvinistic attitude, simply say "no thank you". Very simple, very effective and doesn't cause any bad scenes. Eventually, men will get the hint and stop asking. If you do berate a man constantly, this is likely to hurt the man's pride (pride being the most important thing a man can possess) and will end up becoming overly-chauvinistic.
Think about it, if there is a negative outcome for the male for trying to be nice to the female (which is his intention), then there is very little incentive for the male to be nice to the female in future. This flows on to other areas and actually denigrates gender relations rather than improve them.
In summary, "No thank you". Polite, and he'll get the message eventually but it's going to take time. Just be patient with us stupid men. We're stupid.