Hi Emilio!
You cannot use Mesh without a WLC. However, you can configure a 1242AG to bridge out over the A radio to another 1242AG. This can only be done once, though. You cannot bridge out to more than one AP, and it cannot bridge out to any other APs.
I guess it's possible to do this with 1131AGs, but I've never done it and the internal antennas wouldn't be ideal for such a design.
I hope that helps!
Jeff