Ariel Rocholl has been working with Seed Studio on an affordable handheld spectrum analyzer called the RF-Explorer.
It’s a sort of Swiss Army Knife for monitoring, testing and diagnosing ISM band digital communications. It currently supports the 433Mhz, 868Mhz or 915Mhz bands and other bands in the works. The RF-Explorer is currently in beta with Seeed Studio.
I can see this coming in handy with my water meter reading project.