A bonus to hit and/or to damage due to a character's Strength can be taken into account when that character or creature hurls a missile. 
Such missiles are throwing daggers, throwing axes, spears, hammers, and javelins (not darts). 
To gain a Strength bonus the figure must be proficient with the weapon. 
However, Magic-Users never gain a Strength bonus to hit or to damage from a thrown dagger (aside: Magic-Users must learn to throw a dagger. First- to fifth-level M-Us are -5 to hit with a dagger, whether they like it or not, whenever they try to throw it.). 
A Thief can gain a Strength bonus with a thrown dagger but never if he/she is trying for a "back stab" bonus.

The full bonus to hit and to damage is awarded for targets within 15 feet of the thrower. 

For the balance of the short-range distance, 16 to 30 feet (16 to 60 feet for a javelin) half the bonus is awarded. Halved bonuses are rounded down. 
Giants gain their full strength bonus to damage whenever the target Is within 20 feet (See other notes on Strength In Leomund's Tiny Hut, Dragon #43.)

Specialization
Bows: Fighters and rangers using the long, short, or composite bow as
a special weapon are entitled to a “point blank” range category. Point
blank range is from 6' to 30'. The character is +2 "to hit" and on damage
rolls against targets within this range, and furthermore any successful
hit deals out double damage (a total of 6-16 points for a non-magical
arrow) to the victim, plus bonuses for strength or magic if applicable.
Additionally, a bow specialist who begins the round with arrow nocked,
shaft drawn, and target in sight is entitled to loose that arrow prior to any
initiative check. Short range for a bow specialist is from 30' up to the
lower limit of medium range for that bow. The bowman is +1 to hit and
damage at short range. Bow specialists may also gain additional attacks
at higher levels.