Google has a really good unit converter that essentially only requires you to tell it what to convert in plain English.
For example, I wanted to know how much the cell phone carriers are ripping us off on text messages. Each text message can be a maximum of 140 characters, which is 140 bytes, and each message costs 15 cents. This is what I typed into the Google search bar:
15 cents per 140 bytes to dollars per megabyte
This is what appeared at the very top of the search results:
(15 Canadian cents) per (140 bytes) = 1 123.47429 Canadian dollars per megabyte
So there you have it! We pay $1123.47 per megabyte if the data is a text message.
+1 for Google.
-10 for Telus.