Is there a simple way to figure out which is the first recepticle on a
circuit? I have an older house - the two upstairs rooms are on the same
circuit and are not grouned. Id like to add a GFCI plug on the first
recepticle on that circuit, so every recepticle downstream is
protected.

The brute force method would be to guess which recepticle is the first,
remove the outgoing wires, and test every other outlet for power -
rinse (hook back up the wires), repeat, until ive found the recepticle
that has power and all the others that dont. However this will take
awhile - most arent easily accessible - behind furnitire, beds etc.

I have at my disposal the standard home repair tools - volt meter, etc.

Thanks!