When I format a MS-DOS filesystem using Disk Utility in Mac OS X it takes only a few seconds, but when I format a FAT32 filesystem in Windows it takes several minutes.
What is OS X doing differently?
The format process can be handled differently depending on what the OS actually accomplish by during the format.
Formatting should leave a clean and cleared file system. This can be done very fast by only clearing the file allocation table (FAT). This means writing to a very limited blocks /sectors on the disk.
Alternatively formatting may include clearing all the data previously on the disk/drive. This obviously involves writing to ALL of the disk and is a lot more time consuming.
Windows have the "fast" option and Mac OS X also has the "slow" option - OS X even has options to multi-wipe data with random garbage data (this usually takes forever).