Look at the CONVERT function in the analysis toolpak.

Here's an extract from the Excel 2003 Help file:

Distance From_unit or to_unit
Meter "m"
Statute mile "mi"
Nautical mile "Nmi"
Inch "in"
Foot "ft"
Yard "yd"
Angstrom "ang"
Pica (1/72 in.) "Pica"


Pip pip
Zorba