The Zigview S2 Digital Viewfinder clips onto the optical viewfinder of your DSLR, adding a swiveling live 2.5-inch LCD display that can not only be extended on a cable as a remote, but can also automatically trigger the camera when it detects motion. That makes it possible to mount your camera in odd places or to snap photos of wildlife that might otherwise be sketched out by the presence of a human.
It's only £230, too, which seems fairly reasonable for the amount of flexibility it would add to your rig. The S2 works on a variety of DSLRs from various brands, including Canon, Nikon, Sony, Pentax, and Fuji. (But not, for some reason, on the entry-level Canon Rebel series, which is what I own.)
While you're waiting behind a blind to capture your latest snapshot, you could occupy your time by trying to identify bird songs with this Birdsong Scanning Wand, which plays one of 206 bird song sound files when scanned over the corresponding picture the included booklet. It's $100.
Previously: Wingscapes Birdcam Review (Verdict: Sort of Awesome!) [BBG]