PORTLAND, Ore. - It didn't take long for tickets for a Portland rally involving Democratic presidential candidate Barack Obama to run out.

Officials for the Illinois senator's campaign gave away more than 10,000 tickets online for the Friday morning event at Memorial Coliseum and handed out thousands more at his Portland campaign headquarters, where the line stretched four to five blocks long at times Wednesday.

Those who still want to attend the event can sign up for a waiting list by clicking here.

But even those who got tickets are not necessarily guaranteed to get in when the doors open Friday at 7:30 a.m. The campaign handed out tickets to several thousand more people than can fit in the Coliseum's 12,000 seats.

Obama has attracted a lot more attention this time around compared to his last visit to town in September of last year, where he drew about 4,000 people to a fundraiser and rally at the convention center.

Those who can't get into the Portland event may have a chance to see Obama at another venue in Oregon.

Officials announced Wednesday that Obama will make a campaign stop at the Salem Armory at 1 p.m. Friday. Doors will open at 11:30 a.m.

People can get a ticket by going to Obama's Web site or by visiting the Coffee House Café at 135 Liberty Street in Salem until 9 p.m. Wednesday and from 7 a.m. to 8 p.m. on Thursday.

Obama is also scheduled to speak Friday evening at Eugene's McArthur Court on the campus of the University of Oregon. There are not tickets for that event; people will be allowed in on a first-come, first-served basis. The venue only holds about 9,000 people.

Organizers expect people to start lining up Friday afternoon. Doors will open at 7 p.m.

Other campaign stops in Oregon have not been confirmed yet.

Ballots for the mail-in primary go out in six weeks. The results are tallied on May 20.