This is unfortunate (and it’s rather unhelpful of me to point it out), but how about this from a spokesperson for two dyslexia charities responding to an academic’s claim that the condition is/are in effect/affect not real? I know, the mistakes are the BBC reporter’s and editor’s too:
Once again dyslexia seems to be making the headlines for all the wrong reasons. It is frustrating that the focus should be on whether dyslexia exists or not and claims that it does not is very upsetting to the one in 10 people that it effects.
Effect or affect; its or it’s; compliment or complement. There are some spelling and grammar problems that are so common that they shouldn’t catch anyone out anymore (accommodation anyone?). There are so many harder ones to adjudicate between: adviser or advisor; judgment or judgement, focuses or focusses etc.
PR Studies 
It must be in the air: http://thefriendlyghost.wordpress.com/2007/05/28/affect-vs-effect/
My pet peeve is the use of the word “impact” as a verb. But “effect vs. affect” is a close second!!
Impact as a verb is near the top of the list for me too, as is obligated instead of obliged.
As for words which sound alike but have different meanings, the Inside PRoper English segment of the InsidePR podcast are an excellent source of these.
Terry Fallis also has a go at tautologous phrases from time to time too: general consensus, answer back, etc.
Essential listening for students and experienced professionals alike, I’d say.
Everyone needs a copy of a good reference book like ‘The Cambridge Guide to English Usage’ or something similarly comprehensive.
A lot of it come down to US and UK differences, but much is just plain lazy writing and poor education!
Don’t get me started on how the words ‘burglarised’ and ‘pressurised’ have taken over from ‘burgled’ and ‘pressured’. They just ‘snuck’ in there….
Although you can argue one of the strongest characteristics of English is its democratic/populist nature and its adaptability.