Go to OPTIONS/GENERAL PREFERENCES/ACCOUNT INFORMATION/PREFERRED CONTENT
Change your country settings (content source) to a different one – preferably an alternate English-speaking country, unless you like your ads in Mandarin.
Now sit back and enjoy the completely comprehensible+irrelevant flash ads!
This doesn't 'block' the ads per se, but it sure makes them more interesting! For example, did you know that Vodaphone offers a Samsung E900+512 mb+bluetooth combo for FREE if you sign up for 18 months? It's a great frickin deal! BUT WAIT, it's UK only!
IT'S SO STUPID, IT TOTALLY WORKS!