My dog (20-pound Cavalier) has ridden with me since I got her (she's 2 1/2 now). At first, she fit in my jersey pocket. Then I got a front back-pack -- problem with this is I had to splay my legs to pedal. Then we progressed to a basket on the handlebars. This was great, but she got a little big for that (and it affected my steering). Then, I got a B.O.B trailer. I put her bed in the trailer (and leashed her in). But, I didn't like having such a long extension behind me that I couldn't see (so I've got a B.O.B. for sale if anyone's interested).

The final (and current) solution is a milk crate zip tied to the back rack on my Rivendell Atlantis (my touring bike). It ain't pretty, but it's functional. At the bike show in January, I met a builder who makes custom racks and baskets -- Ahearne. He said he could make something for Julie (which would look better on a Rivendell than a milk crate).

BTW, we only ride to the park and the bike shop where I work and occassionally to the dog park. Since I work at a bike shop and bring my dog to work, I wanted a solution where I didn't have to drive.

With every option I just listed, our first few rides were to to park to play. This reinforced a positive experience for her -- getting on the bike means we're going to have fun!