I use to work in little tokyo at 340 E. 2nd Street and there is a private parking next door (5 Star Parking) lot on 350 E. 2nd Street which is approximately 2 blocks south east from the rallly point. Cost is about $8.00 all day.
Likewise, there is Joes Parking lot (across Bank of the West) on 2nd and San Pedro which is probably a lil cheaper and closer to the rally point.
I'll try to make it to the rally but no guarantees since I have a job interview that day in the OC. Perhaps afterwards if possible...
BTW: watch your meter parkings since the police will not hesistate to tow.