Have you been living under a rock? I live in Australia and knew o2 3G has been having issues.
In saying that they are working on fixing the speed issue according to a statement they put out to the public...
Mine has been bad all morning, North West here.
I'm with Vodafone (who now share masts with 02) based in central london and ever since the iPhone came out on Vodafone the network has been crippled to the extent that Vodafone advised me to turn of 3g until its resolved
Seems to be a lot of grumpling now about the lack of proper 3g infrastructure
http://www.bbc.co.uk/blogs/thereporters/rorycellanjones/2010/01/the_3g_traffic_jam_where_next.html