It's completely different. FONERA aims at creating a global network of free wifi everywhere. To participate you need to buy a FONERA router. Wifis.org is simply a way to communicate with the wifi network owner. You just need to rename your SSID and your neighbors can now email you.
Oh, haha. I wouldn't have guessed something that simple.
People could just name their network after an e-mail address if they wanted to be contacted..
I would say wifis.org is "cutting out the middle man" and you don't share with an anonymous global community, but rather locally with someone you probably (get to) know. Also, its potentially free.
Personally I see the biggest use case in moving and temporarily needing a wifi connection until your real ISP can hook you up.
In the UK FON is everywhere due to it being defaulted to on with BT Internet for the last few years (BT is one of the most popular ISPs and also runs the landline phone network)