[joshvm]

http://www.redspottedhanky.com/ is supposed to be quite good for that, though I've never used it.

Never use The Train Line. They charge a booking fee. Just your local train operator, they all use exactly the same system, same database, etc but you won't pay £1 to buy the ticket.

[kzar]

Oh I didn't use them to book, only to check which train I needed to catch.

[joshvm]

In that case I just use National Rail, the website is well optimised for mobile.