I vaguely remember a prc from one of the completes that is tracking based. Bloodhound or something.
I'm pretty sure it's Complete Adventurer. I think it's a reprint from Masters of the Wild. I haven't looked at either version in years, so I don't remember which is better.
Yes, its Complete Adventurer. Bloodhound gets swift tracker at level 1, 3 levels earlier than Ranger, and gets the ability to track creatures under the effect of trackless step at 5. Also has extra tracking speed for creatures he's studied (or studied the likeness of) for at least 10 minutes (may require autohypnosis to be actually useful). Pretty sure the Masters of the Wild version was better though.
Other Track boosters:
Shaaryan Hunter from PGtF can track while mounted, initially at half her mount's speed without penalty, then at 6th level at her full mount's speed.
Consecrated Harrier from CDiv allows you to always know the direction and approximate distance (within 10%) of any creature you've ever wounded at level 8 (ECL 13) and at 10 can track across planes as well. Other than that a sub-par class.
Spell-wise, there is Bloodhound (Ran 1) from CAdv, which lets you re-roll a failed track check; Implacable Pursuer (Ran 4/ Blk 4) from CDiv, which is pretty mediocre for its level because you must target the creature initially, but after that you know its exact location every round, or even what plane it traveled to if it changes plane. Living Prints (Ran 3) from MoF negates any passage of time since the tracks were made, which is essentially just a bonus to track, but it can be massive if it has rained a lot, snowed, or just been a long time (max 30 days). Also the duration is 1 hour/level.