For a current list of the gears look at hedgewars/uTypes.pas at
the TGearType enumeration.
{{{
    TGearType = (gtATFinishGame, gtATSmoothWindCh, gtATStartGame, gtAirAttack, 
            gtAirBomb, gtBall, gtBallGun, gtBee, gtBirdy, gtBlowTorch, gtBomb, 
            gtCake, gtCase, gtCluster, gtClusterBomb, gtDEagleShot, gtDrill, 
            gtDynamite, gtEgg, gtExplosives, gtFirePunch, gtFlame, gtFlamethrower, 
            gtGasBomb, gtGirder, gtGrave, gtHammer, gtHammerHit, gtHedgehog, 
            gtHellishBomb, gtJetpack, gtKamikaze, gtMelonPiece, gtMine, gtMolotov, 
            gtMortar, gtParachute, gtPiano, gtPickHammer, gtPoisonCloud, gtPortal, 
            gtRCPlane, gtResurrector, gtRope, gtSMine, gtSeduction, gtShell, 
            gtShotgunShot, gtShover, gtSineGunShot, gtSniperRifleShot, gtSwitcher, 
            gtTarget, gtTeleport, gtWaterUp, gtWatermelon, gtWhip, );
}}}
Note: gtBomb and gtShell were named gtAmmo_Bomb and gtAmmo_Grenade before 0.9.14