What are the most effective methods, mechanically, to quickly give a fighter useful magical knowledge and options (in and out of combat) without significantly sacrificing effectiveness as a fighter? Items are out, as they're not strictly part of a character build.
- Take a level in a martial casting class (ie. Duskblade)
- Minor retraining for more appropriate feats (ie. Book of Iron Might, Spelltouched feats)
- Rebuild at level-up (ie. Fighter6/Cleric5)
In my group's current game, I play a half-orc Fighter10. Character-wise, he's a professional expeditionary guard for academic expeditions who's already died once (plot point, potential excuse for magic). The setting is a modified Eberron.
We're about to level up, and I've been thinking about branching the character out. There's a lack of utility characters in the party. Given my character's history, I'd like to increase his knowledge skills, as well as utility magic.
Note that I'm not asking for help building or playing a fighter. I'm asking for specific suggestions to give a fighter knowledge and magical options without completely rebuilding. (Single-level dips are fine.) Think mechanical reflection of character traits, not strictly optimization.