This is deviating slightly from what magic may be in your campaign, but using the super power system presented in Four Color To Fantasy is a viable alternative.
A new core class, the Hero, is introduced. At each level, the Hero gains points that can be spent on various super powers. These powers can take nearly any form, from evergy blasts to flight to teleporting, and more!
The system is extremely flexible, and doesn't presuppose a specific type of campaign - you can use it in medival fantasy, modern campaigns, or whatnot. Since only the mechanics of the powers are set in stone, you can easily make the source whatever you want. There is even a set of enhancements and restrictions, one of the restrictions being how to make the powers magical in nature so they're vulnerable to dispelling, anti-magic fields, etc.
It's definately a supplement worth looking into, for any campaign, either in addition to, or to replace, another magic system.