Kris Allen says returning to "American Idol" on Thursday (Feb. 25) will be nerve-wracking, but a good cause makes it worthwhile.

The Season 8 champion will be the special guest on "Idol's" results show, taking a moment away from the elimination of four contestants from the top 24 to sing. Allen also plans to talk about his recent trip to earthquake-ravaged Haiti and get viewers to phone in relief contributions during a mini version of the "Idol Gives Back" concept.

See Photos of Kris Allen's Trip to Haiti

"The thing about it is, it's not about me," says Allen, who had a missionary background before competing on "Idol." "Every time I was on that stage last year it was about me, and for this is not. It feels like a really good thing to come back there for."

Allen -- who visited Port-au-Prince last Friday under the auspices of the United Nations -- will perform the Beatles' "Let It Be" during the episode, which will be sold iTunes with proceeds going to the Foundation. Viewers will also be able to text message contributions. The UN Foundation is in need of funds not only to help rebuild Haiti but also to help the populace survive the coming rainy season which will hamper reconstruction efforts.

While in Haiti, Allen handed out rice bags and visited temporary shelters, including one where he sang "Amazing Grace." He plans to talk about the trip on "Idol" as well as show some footage. "When you see something like that, it definitely affects you," he explains. "It makes you happy for what you have, and it makes you want to do something to help those people. I think it's an innate human kind of thing; when you see people hurting, you definitely want to help them.

The most lasting memory of Haiti, Allen added, was a visit to a tent where mothers were caring for their children. "It felt like a really safe place," he said. "They were taking care of their babies, which were from newborn to two (years old) or something like that...That just seemed so happy. It was a really cool experience."

Back in the music world, meanwhile, Allen is still actively promoting his self-titled post-"Idol" album, which is nearing the 300,000 sales mark. He said there's "definitely some talk" about a follow-up single to 2009's "Live Like We're Dying" but added "we don't have anything set in stone."