I have a 16Mbps connection, which should be around 2MB/s. I hardly ever get that on downloads; I attribute it to inefficiencies in my router/modem/cords combination but I'm probably wrong.
Mbps = megabits per second
MB/s = megabytes per second
8 bits = 1 byte
so your Mbps speed divided by 8 is your MB/s speed
so if you have 4 Mbps, it will take you 2 seconds to download a 1 MB file.
Just to clear things up for the people who dont already know the difference