If you're dead keen on nature, but you're also dead keen on your sofa and not going out into the cold and rain, then you might be interested in this product from Cornish specialists HandyKam. It's a Cedar birdhouse with an intergrated feeder, but also an integrated colour digital camera.
The birdhouse comes fully assembled - all you've got to do it put it up a tree, add the camera into the fake ceiling of the construct, and then wire it up with the 20m composite cable provided. If that's not quite long enough, then they'll happily sell you 10m, 20m or even 50m more. Power is also supplied via this cable.
The camera supplied has integrated IR LCDs, so when it's dark out, you'll still be able to see what's going down in birdland. It's PAL, as you'd expect, has component out, and features a 420 line CCD chip with 1/3" sensor. It's all very damp-proof, as you might expect.
Wanna see the kind of footage it can capture? Of course you do. Here's a video, though bear in mind that most of the day you'll just be staring at an empty box, especially out of nesting season:
It looks like a decent product, it's available now, and is currently discounted from £151 to £106. Not bad.