Got bored so I threw one together.
It loads a source file, removes any duplicates, verifies that each entry is only numbers and periods, then generates a new list based upon the range you supply.
Will require VB dependencies MSVBVM60.DLL and COMDLG32.OCX which most of you probably have already anyhow.
http://www.dynamixxx.com/complete/software/ipRange.exe
