The following file is complete except for the art.
Another possiblity is, if you have access to GURPS Spirits, to use the old Spirit Magic system in place of the newer form of Ritual Magic in 4e or to supplement the new system.
There is big collection of new spells on Patyrsuns page. They are meant for GURPS 3e, but they can be converted with ease.
(original entry by Dr Temp; resulted from a SJG web forum discussion thread to which many people contributed)