George Harrison wasn't exactly a fan of being "on the road." After the Beatles' final tour in 1966, he toured only twice as a solo artist. Twice! There was his 1974 tour of the U.S. and his 1991 tour of Japan. That's it.
Outside of that, Harrison's official live performances were limited to special events, including the 1971 Concert for Bangladesh, the 1987 Prince's Trust Rock Gala and his April 6, 1992, benefit concert for the U.K.'s Natural Law Party at the Royal Albert Hall. Harrison's shows were so rare that this '92 concert turned out to be his last full-length show, ever.
Although the Heartbreakers' Mike Campbell handled a lot of the six-string heavy lifting that night, Harrison brought out guitarist Gary Moore as a special guest for the show's pre-encore finale, the Beatles' "While My Guitar Gently Weeps." As always, Moore did not disappoint, delivering a truly blistering solo on the classic White Album track.
Harrison and Moore were hanging out and recording together fairly often in the early Nineties; Moore played on the Traveling Wilburys' 1990 album, Vol. 3, and even recorded a Harrison composition, "That Kind of Woman," which appeared as a CD bonus track on Moore's much-loved 1990 album, Still Got the Blues.
Below (top video), check out a poor-quality clip of Harrison and Moore (with Ringo Starr on drums) trading solos on "While My Guitar Gently Weeps" at the Royal Albert Hall. They're both playing very attractive Gibson Les Pauls, which is something of a rarity for Harrison in this period (I suspect they both belonged to Moore, but I'm not sure how I can verify this at the moment). The first guitar solo starts at 2:08; the long solo at the end starts at 3:36.
Below that (middle video), you'll find the music video for the Traveling Wilburys' "She's My Baby," which features Moore on lead guitar (although he doesn't appear in the clip). His solo starts at 1:29.
The bottom YouTube player contains Moore's version of Harrison's "That Kind of Woman," which features Harrison on slide guitar; the two guitarists even trade off on the solo, which starts at 1:50. By the way, "That Kind of Woman" was originally written for and recorded by Eric Clapton during Clapton's Journeyman sessions. Harrison plays on that version too.