few weeks ago one of the partners of one of europe's largest VCs told me that he couldn't concentrate at my pitch because i sounded to much like http://vimeo.com/7595897

This kinda kept sticky in my mind. ;)

As i am moving now with my company[1] to London i would like to use this opportunity to improve my english, my accent and my grammar/spelling.

As a typical non-native i have regular problems with spelling e.g. with similar sounding words. I do have this problem especially in hectic faces.

Additionally I have trouble with incorrectly translated german expressions. Some of them are really below all pigs.

How would you suggest to level up english in a time efficient way?

Are there online services/startups you would suggest? Do you have other experiences here? (e.g. writing blog articles?) How did you improve you (once mediocre) english?

ps: i left by intention more than 4 mistakes in this post just to prove my point.

[1]: My Company - http://www.Garmz.com - Feedback Thread: http://news.ycombinator.com/item?id=1788016