Yardly:
Also, isn't there a Ring of Cantrips already?
I'm sure it's in the Encyclopedia Magicka
Yes there is, corrected my post above.
Ring of Cantrips (Magic Ring)
Similar rings are known to exist, and are usually made of brass engraved with symbols inside and out.
While wearing one, a wizard or bard can cast any cantrip magic, as described in the spell description.
The wizard may create 1d4+4 effects per day, and each effect lasts as long as the wizard concentrates.