Advice?

Hi all,
I'll be relocating to Portland,OR in July and since I'll be close enough I want to try to attend the Bay Area Carnivorous Plant Society meeting in August. My question is, does anyone have any advice for the cheapest way to travel from Portland to Berkeley?
I'm not familiar with travel in the lower 48 and I have no clue. I won't have a car and last I checked they don't let you rent one at 20 years old.
Any advice?
Thanks in advance...

Do they have a bus?

You might want to check into Amtrack or other trains. They will probably be a better option then a bus trip. If you are planning to make a trip from oregon to california, you should make the most of it since the ride by ground will be on average 8-10 hours (traffic, weather, etc will need to apply)