We study the radical cations of a-cresol, which display interesting differential red shifts for the species in which the OH is inclined toward or away from the neighboring methyl group. We review four possible explanations: hydrogen bonding between OH and methyl, open shell effects, electrostatic environmental effects, and the perturbative admixture of antibonding sigma MOs with the OH local bond orbital. The apparently analogous difference in the IR absorption of the OH stretch of cis- and trans-o-fluorophenol is easily rationalized by electrostatic effects. Methanol-methane radical cation shows a strong attractive interaction and has the linear X-HA arrangement and extended HA bond length characteristic of H-bonding. The cresol radical cation displays neither feature. Neither of these systems is a helpful analogy to o-cresol radical cation. The perturbative admixture of antibonding orbitals with the OH local MO provides an effective rationale for the o-cresol phenomena.