None-class based Spellcasting Advancement?

[Vaz]

Is there any way to get an advancement to your spell casting class without taking another level in the class or prestige class?

My build is at CL16, at 20, and I would love to have it get to CL17 for 9th. Is there any way for me to do so without dropping one of my other classes for further advancement?

[Radar]

Bloodlines (http://www.d20srd.org/srd/variant/races/bloodlines.htm) abuse allows you to advance class features without increasing your level. Keep in mind they are considered severly broken and not very well written.

[Vaz]

My eyes are bleeding from attempting to read that, was bring your kid to work day or something when they wrote that.

[Mato]

Most of the stuff printed in UA is revised Dragon Mag content. So if you think that's bad, you could always try tracking down the Dragon version...