I'm also a user of foobar2000 and I have a collection of ~2400 songs, mostly in FLAC. With my iPod I have a great extension that syncs all your music (or selected playlists) and will encode the FLAC down as well, so I wanted something similar to that.
I looked all around but it appears there just isn't anything out there yet, however I found something which is close enough. Using foobar2000's built in "converter" utility, I set up a preset which will:
Encode all the selected songs to V0 MP3
Copy them into my phone in the Music\Artist\Album folder
Copy the album artwork into the folder too
So after clicking that and waiting, I'm ready to go with that music on there. Of course, the main disadvantage of this is that every time you add something to your music collection you will need to manually go in there and select it to be converted. Space wize, I can't afford to keep all of my music on my phone even in V0 MP3, so when I get a new album I won't necessarily want to copy it onto my phone.
Anyway, if you want the settings for my preset thing then I'll happily give them to you.