Use a delay pedal. This effect is what provides the classic, electric "bounce" of the Edge's guitar in older U2 hits like "With or Without You" and "Still Haven't Found (What I'm Looking For)." The delay effect was one of the elements that helped make U2 a superstar band in the 1980s and 90s, and it pops up in a lot of the work in between the "October" and "Rattle and Hum" albums.
Try a "walking solo" like the one in "Sunday, Bloody Sunday". In this classic U2 ode to violence in their home country, the Edge uses chromatic steps to create a sound that is both Irish and American, a rock-solo with a somehow Celtic sound.
Get gain. In addition to the driving percussion of Larry Mullen, the Edge amps up U2's sound with crashing, groaning, and wailing guitar sounds that give some U2 melodies an epic quality, like the musical drama "Bullet the Blue Sky." Later, the Edge uses gain in songs like "Numb" on the "Zooropa" album in a minimalist, slowed-down approach to create a very different feel.
Try experimental guitar. The albums "Zooropa" and "Achtung Baby" include a new kind of U2 sound as the band marched on into the 21st century. You can twist the delay to imitate the sounds on songs like "Ultraviolet (Light my Way)" or tone down your sound for gritty dirges like "Love is Blindness" or "Dirty Day."
Go fast. The newest U2 hits, songs like "Beautiful Day" and "Vertigo" as well as the New Orleans anthem collaboration, all have a rapid sound, an intense adherence to a "new-rock" rhythm that keeps on going. The "Beautiful Day" track evokes the ambiance of an airplane leaving the runway and arcing up into a blue sky. Try to get this upbeat feel into your music.