Debating a SIN mileage "run" (where I'll actually get a full day in the City). Flight arrives at 23:45 and departs 7:20 (no not the next morning - I have 2 1/2 shreds of sanity left).

(1) What's the best way to my hotel? Taxi? Shuttle services? Approx. cost and time?

(2) What's a "safe" amount of time to be at the airport for the return?

(3) How would you spend a "day" in SIN (on little sleep, not staying out late).

Any other SIN tips would be appreciated. I know there's some "mileage run" stuff about SIN and there's some more specific forums, but really, who goes there.....