"KB" stands for "kilo byte".

* The "B" should be dropped, because this will not only be used for bytes.
* The "k" should be lower case to match SI prefixes, at least when we're _printing_ it. Since for some metrics, like "milliseconds", we need to make a distinction between upper- and lowercase, I'm not sure if we should even accept uppercase "K" from the user …
* For completeness sake, we should add "T", "P" and "E". "Z" and "Y" don't fit into 64 bit variables and it's not worth to go through all the trouble required to implement them.
* Some of the smaller prefixes may also be interesting. We should at least add "m", "u" and "n".
* Last but not least: "1k == 1000". For special cases where you want to have binary prefixes, you should implement "binary prefixes", i.e. "Ki" ([sic], for some reason they decided to make that one uppercase), "Mi", "Gi", … http://en.wikipedia.org/wiki/Binary_prefix