Here's my tactic for meeting girls on public transport:
1) Choose a seat where you'll be in her Public Space (
http://en.wikipedia.org/wiki/Personal_space) and can make eye contact even if you need to turn around.
2) "Hey, excuse me do you know..." Initial interaction.
3) Observation, she laughs
4) More personal question; "Actually, you might know the answer to this too..."
5) Excuse to sit next to her. "Sorry, do you mind if I move over, I'm going to end up with neck injury if I have to keep turning around to speak to you".
6) Because of how close the seats are, she'll get nervous when you sit next to her because you've just jumped way within personal space. The usual reaction is to ignore the person who's just done this, you need to relax her by making her laugh quickly.
Now continue as you would with any other pick-up.
Let me give an example:
You walk onto a bus and scan before showing the driver your ticket. You notice a HB with a vacant seat in front of her. You sit down.
"Hey excuse me, do you know where *a coffee shop* is?"
Her answer.
"Aw man, I'm going to get soaked. I never remember to bring an umbrella when it might actually be useful"
...
"Hey, cool handbag. Where'd you get it? I need to get my niece a great present for her birthday"
*talk for a while until bus stops and old people get on*
Ask old people if they'd like your seat. Move next to girl.
And you're in.
Things to remember about public transport
- people deal with invasion of personal space by ignoring the intruder as much as possible.
- don't leave the girl feeling cornered and that she has to keep talking to you. Have a book that you *clearly* want to get get back to once you finished asking the girl about whatever pressing matter you've found.
- everyone will overhear your conversation. None of the options that you want the girl to take should make her feel slutty. If anything, you want the girl to feel like all the other girls are jealous that you're talking to her and not to them.
Finally, I should preface this by saying that this is based on my own experience of British public transport. It may be different elsewhere in the world.