Mine is 7434.10 miles. The cache (GCW402 - Jebel Ali Jumble) is in Dubai, UAE. I managed to get two of them there with no GPSr. A very understanding taxi driver, a smartphone with the downloaded maps and sattelite photos, and the cache descriptions saved on the phone got me the finds!
I also managed to get one in Amsterdam - 4884.39 (GCXNEC - AMS2 - Nooit Meer...) on a layover on the way home!
Not too bad for a business trip...