I just got a Pentax 1degree digital spot meter for under $300. I am still new to guesstimating my exposures so I want something I can trust. Also, I've been carrying my Canon 5D Mark II as a "spot meter' and it's way heavy and quite expensive for that purpose. Plus it defeats the purpose since I get lazy and want to go for instant gratification, something I've been trying to get away by switching to film. Also, when it comes to the iPhone app, you might want to consider where you shoot. I do most of my shooting in the Rocky Mountains and have limited to no service making the apps I've tried useless. If anyone can recommend an app that doesn't need service I'm all ears.