Yes I had this same problem recently too, I used the first google result for a free converter if I'm honest as I didn't care particularly about the quality of the files and it worked.
I tried flux or flax? The 'plugin' for itunes, all it did was crashed so I removed it.
Did you guys know that there is a Mac version of Winamp?! I certainly did not know until I came across it last week-end. I do not even recall how it happened. Perhaps that could be of a fit for you guys who need FLAC support?
I use dbPowerAmp free edition to convert batches of flac to Apple Lossless for iTunes. It's trivially easy, and can even convert the apple files back to flac and compare with originals to confirm that nothing has been lost of corrupted in the process. Strongly recommended (I have no connection with this product or any company connected with it!)