There is a 'mini loan' service, just I do not know if it is part of FNL or not. It is about getting a device for 4-6 weeks (depending where you live). The only cost arises when you send it back by post.
The completely free approach is RDA. It is open to everyone, no membership in any developer program is required.
Although there are things like BeagleBoard (
http://beagleboard.org/), generally it is hard to specify a hardware which is both cheap, and is able to support any hardware configuration. Getting firmwares is also problematic. Generally it is more useful to those who build mobile phones than to those who write software for them.