#23 and #22 - I like the shape of the logo with the rounded and sharp corners. i also like the shading/bubble look on the upper left. I would like to see you add "San Jose" and 2012 to the logo some how. These are important elements to include.
#21 and #20 - I do like these - I could almost see using #20 and #22 - depending on if I was using them on the web, on a flyer, in a brochure, or as a lapel pin. I do need you to add "San Jose" and 2012 to these.