>Another one, which is actually two. What's the plural of 'mouse' and 'louse'? 'Mice' and 'lice', right? Two don't make a rule yet, but... let's try:
>
>mouse - mice
>louse - lice
>spouse - spice
>nouse - nice
>douse - dice
>house - hice
>twouse - twice
>polouse - police (OK, this is a bit stretched)
>rouse - rice
>ouse - ice

You left out Foot/Feet and Tooth/Teeth. Can't think of any others.

Alex