I appreciate this may not be to everyone's tastes, but I find the the following very very exciting!
Over at GoogleMapsMania I found out about the AIS ship tracking system, which is required for all boats over 299GT, but presumably fitted to quite a few under this too. Anyway, this information is overlaid on a map and displaced in realtime at ShipAIS, with maps of the whole of the UK (I've linked to the Medway one in front of our house!)
Hover over a boat and a box pops up telling you name, speed, direction, what it's up to, where it's going, and what kind of boat it is, which usually gives away its cargo too. Oooooh! The reason I find it so exciting is that our house looks out over these boats drifting across on the horizon, so it's natural to be curious as to what they're up to, especially the particularly large ships. Now we'll know!