Base Calculator:

Located on the Tools menu, you probably won't have mush use for this option, but it's good to know it's there if you ever do need it.  It will convert numbers you enter into the different bases - Hexadecimal, Decimal, Octal & Binary.  The only time this might come in handy for stationery is if you need to manually convert some colour values from decimal to Hex, or vice versa.