As weaponlights get smaller and smaller, yet retain the power of their much larger brethren, ever-greater options become possible. More and more holster manufacturers are designing holsters to accommodate weapon-mounted lights/lasers, too, so it becomes easier and easier to equip your daily carry with these devices.
Streamlight's TLR-4 offers a 125-lumen light and a red laser in one small package (2.8 ounces), with a green laser variant also available. The light has a 1.5 hour run time, while the laser has 11 hours on. A toggle switch at the bottom of the unit can be set for laser-only (left), light-only (middle) or light and laser (right).
Activation is accomplished one of two ways. Turning the lever counterclockwise for momentary activation, while turning it clockwise to a click engages the light/laser for constant-on. Activation of the TLR-4, for a right-handed shooter, is best accomplished with the thumb of the support hand (assuming a thumbs-forward grip), either for momentary or constant-on.