I read with interest many of the blogs from the otherside of the Atlantic and get a very different view of Roleplaying as a hobby. There seems to be much more of a focus on playing commercial modules, and less about creating your own worlds and adventures. How an industry which creates a rules system which offers you the opportunity to create your own world full only limited by your imagination manages to sell more product has always puzzled me. Once I've bought the core rulebooks for a system I've usually written my own scenarios and source material (with the exception of Cyberpunk which I just loved).
Also the con scene is quite different in the UK. Single day events being the norm and sharing fans across the gaming spectrum including wargamers, boardgamers and the odd sci-fi con.
The most startling difference is in my experience of how gaming groups are formed. I've always gamed in large groups of between 10 to 20, congregating in public spaces such as church halls, libraries, community centres and even the odd public house (aka a bar). I've hosted games at my home but these have always been as an extra to my regular weekly game session as part of an organised club.
I can guess at one or two of the reasons, America is a much bigger country with a lower population density than the UK, but this doesn't explain everything. If you're reading this from the US (or any other part of the world) please feel free to set me straight.