Barclaycard OnePulse
A credit card, Oyster card and cashless payment card all rolled into one.
http://www.barclaycard-onepulse.co.uk/

Disabled Persons Railcard
Discover how you can travel on British trains for less, if you qualify.
http://www.disabledpersons-railcard.co.uk/

Family Railcard
Save up to a third on British train fares.
http://www.family-railcard.co.uk/

Oyster Card
Avoid the queues at the ticket counter by buying one of these rechargeable smart cards for getting around London.
http://www.oystercard.com/
http://www.oystercard.co.uk/

Qjump.co.uk
Buy your train tickets online.
http://www.qjump.co.uk/

Senior Railcard
Discounted rail fares for pensioners.
http://www.senior-railcard.co.uk/

The Trainline
Online train ticket vendor.
http://www.thetrainline.com/
http://www.internationaltrainline.com/

Ticket On Line
The "Visitor Travelcard" allows you to travel on all public transport in London using just one ticket. Buy it online here.
http://www.ticket-on-line.com
http://www.londontravelpass.com/

Transport for London
Foreign visitors to London can purchase the Visitor Travelcard online and enjoy travel on the city's public transport, including the Tube and bus, with a single ticket.
http://www.ticket-on-line.com/

Transport for London
Use the "New Fares & Tickets" section of this website to find out about the latest fare prices and ticket types, and which one suits you.
http://www.tfl.gov.uk/tfl/

UK Public Transport Information
Public transport web resource for the UK. The site includes timetables and information on fares, ticket types and facilities.
http://www.pti.org.uk/