Here's what I'm thinking:
-Lower the voting age to 15. Arguments for this age include: many 15 year olds have part-time jobs, pay income tax, can be tried as adults for violent crimes, etc.
-Draft a resolution and submit it to either City Council or the Board of County Commissioners (BCC). I think both have their benefits. The BCC is generally more supportive of youth causes, but there might be some outcry from East County. Portland is geographically smaller, which would make organizing easier. Maybe shoot for both jurisdictions? I imagine one would adopt the resolution shortly after the other, anyways...
-It'd be advantageous to time this right before an election. The officials who vote in favor of the resolution could be persuaded by all of those youth votes that'd be freed up... In 2008, two BCCers (Naito and Rojo de Steffey) are up for reelection, as well as two City Commissioners (Adams, Leonard) and Mayor Potter.
-So, 2008 seems like a good target year.
-In the mean time, allies need to be identified and united. Youth, civil rights, and civic groups. Oregon Bus Project, City Club, Leaders Roundtable, Students for Peace and Justice, Portland Youth Alliance, Multnomah Youth Commission, etc. Get some national backing, too: National Youth Rights Association, Arsalyn, Mobilizing America's Youth, etc.
If you're interested in getting involved with this effort, email me!