I have been implementing GTD for nearly a year now, I use a paper system and I always try to add improvements to my system.

One of the recent things that I've added is the "Today List" this is simple, but very effective way on focusing on the tasks that I have to process in my day.

Basically, at the start of each day I go through my @context list and add 3-5 items to my "Today List" and try to hang in next to my PC, where I can easily view it thought out the day.

I actually learned this from the "Thing" software for the mac, where you can drag tasks to a today sidebar.