In the'70s, it was Farrah Fawcett and her locks; now Nancy Reagan's hairdresser, Robin Weir, says it's something quite different. For the past week and a half, Weir's Georgetown salon has been catering to young folks anxious to get the "Ollie Cut," commonly described as "buzzed on the sides, and a little longer on top."

And for those who haven't gotten enough from television, print and radio, Pocket Books will soon be out with Lt. Col. Oliver North's testimony in book form. "Taking the Stand: The Testimony of Lieutenant Colonel Oliver North" will be on the stands a week after North's last day of testimony. It's going to sell for $5.50, and the first printing will be a minimum of half a million copies.

Alf Landon's Birthday Wish

Former GOP presidential candidate Alf Landon, father of Kansas Sen. Nancy Kassebaum, has invited President Reagan to his birthday party in September. Landon, who lives with his wife Theo in a stately mansion in Topeka, Kan., turns 100 Sept. 9.

An aide to Kassebaum said Reagan would be at his California ranch for the Labor Day weekend and it was hoped he would visit Landon on his way back to Washington. White House spokesman Marlin Fitzwater said the president is "considering making the trip."

Of House and Holm, Cont'd

Peter Holm, who had threatened to shoot anyone who tried to oust him from the Los Angeles house he once shared with his wife, actress Joan Collins, walked out of the hillside home last night just before police arrived to evict him.

"I am a peaceful man," said Holm, who earlier had told reporters that all the doors to the house were barred and that anyone who tried to enter would face a "battle."

The onetime Swedish rock singer, who is engaged in a bitter divorce action with his estranged wife, says he has nowhere to go.

"We have to go to the car and I have to decide what I'm going to do," Holm said as he left the house. "As far as I'm concerned, I'm right out here on the street and I don't know what I'm going to do."

Wasserman Recovering From Surgery

Lew Wasserman, one of the last surviving old-time movie moguls and chairman and chief executive of MCA Inc., was listed in "very satisfactory condition" yesterday after undergoing surgery two weeks ago to remove a polyp from his colon. The prolonged stay, however, doesn't indicate that the 74-year-old Wasserman has run into complications, said Ron Wise, spokesman for Los Angeles' Cedars-Sinai Medical Center. "He is doing very well," Wise said, and his "prognosis is excellent."

Wise added that the results of tests to determine if the polyp was cancerous were not being disclosed. The Bakkers Pack Up

Jim and Tammy Bakker quietly returned yesterday to the $1.3 million PTL-owned home they once occupied in Tega Cay, S.C., apparently to begin packing for a move to Tennessee.

The couple, who spent the past 2 1/2 weeks in the Great Smoky Mountain resort of Gatlinburg, Tenn., did not talk to reporters outside the house. They had said earlier that they planned to return to Tega Cay to gather their belongings before returning to Gatlinburg to live.

Meanwhile, newspaper editors in the Gatlinburg area say the Bakkers' stay in Tennessee has heated up their letters-to-the-editor columns, with opinions running 3 to 1 against the former PTL evangelists.