When can you trade eggs into FRLG?

[phantomness]

Do you have to wait until you can get to 4th island...?

 

[Dual]

I would assume as soon as you set up the machine on the first island that let's you trade with Hoenn.

 

[phantomness]

Really? *ponders* So that's... not for a long while.

 

[Turtle Tamer Kammy]

I know. It sucks hard. I'm playing Emerald right now and am dyyyying for a Squirtle. :<

 

[Silktree]

Eggs can be traded to FireRed and LeafGreen as soon as the National Dex is obtained (which means having defeated the Elite Four and caught 60 Pokémon). Of course, this is the point when you can reach Four Island and breed for yourself.

Obviously, until the Ruby and Sapphire items have been collected, those eggs will have to be traded from other FireRed and LeafGreen games. However, they can very well contain Hoenn Pokémon.