The OP asked about disabling iPhoto from launching on a device-specific basis (i.e. launch iPhoto when I plug in my Nikon, but don't launch iPhoto when I plug in my iPhone). Unless I missed a feature of Image Capture, the setting you describe is global (i.e. for all devices).
One thing y'all may want to check is whether or not iPhone will sync photos without having to launch iPhoto. You won't be able to pull photos off your iPhone (which is why I use the configuration above), but I'd be interested to see if syncing albums works.
Thanks to all who've posted but Kabeyun is correct - all the options above do not reach the desired state, as they either disable automatic syncing, or turn off all iphoto auto-imports with image capture, which I don't desire to do with my nice little cannon digital rebel
I think the smart photo album idea is probably the best way to go, and keep the camera roll as clean as possible, as everybody I run into wants to see the pictures the phone takes, so of course it would be nice to have them on the phone
In the grand scheme of things, this is a minor annoyance, but I figured there was some way around it that I wasn't thinking of
Thanks again everyone !