On Anon is right off Piccadilly Circus, conveniently located at a junction of numerous Tube lines. Follow the Shaftesbury Ave exit at the tube station and On Anon is just a few feet away on the right.
Go in the front door and go immediately up the stairs -- we'll be waiting at the bar on the first floor (the UK first floor, meaning the US second floor!). You can't miss us! Fellow Americans will be easy to spot and we'll keep a look out for new faces and our ears open for the familiar accent.
Questions? Post here or send me an email and I'll try to help.