Savage Species page 121-122, Insectile Creature template gives +4 arms. Needs Multi-whatever Fighting feats though.
Not a bad template either, +4 Dex, +2 Wis, you get to be an aberration, +4 spot and are never flanked, climb speed = land speed, tremorsense, darkvision, +2 natural armor.
I've played one of these for +0 LA, making a Warforged an Incarnated Construct (the template immediately before this insectile), and then adding insectile.