I've gotten off the train enough times in Palo Alto to know how about the "secret" bike bridge over San Francisquito creek, a back door connection between Menlo Park and Palo Alto. This gets you as far as the Stanford Shopping center, which you can skirt by without too much traffic, and get to fairly good bikeways through Stanford campus.
From there to Mountain View, I tried to plan a route with the VTA's online bike route map, which showed me what I had already noticed, that there's a decent bike path parallel to the CalTrain tracks (on the SW side) starting at the Palo Alto station. This connects to Park Blvd, which also Parallels the tracks, and gets you through almost, but not quite to California Street in Mountain View.
Alas, there seemed to be a disconnect where I'd have to jog over several blocks and ride on El Camino (ick). Google Maps to the rescue--on the satellite view, I could just work out that there would be some way to get through the gap, maybe by going through a parking lot.
In fact, there's a creek there, named Adobe Creek. But unmarked on any of the maps I'd seen, including the VTA's bike map there's a nice ped/bike bridge over it, connecting the gap between "Wilkie Way" and "Miller Ave".
In no time at all I was at San Antonio road, only blocks from work, but on a sudden impulse stopped at Dittmer's, a German Sandwich Shop/Deli/"Wurst-Haus" where I used to go for lunch in less health-conscious days. The aroma of tasty sandwiches was a temptation (I recommend the BLTA; "A" being for avocado), but I stuck to my mission and got a couple of cans of pickled herring. I don't know why, but a craving for pickled fish has been overtaking me lately, and this is the only place I can think of to get it. Anyway they're safely stashed in my desk for future lunches (my wife thanked me for indulging this craving at work instead of at home where she'd have to smell it...).
So here's my updated bike ride map, with my third route in red:
As an aside--I knew Palo Alto was posh, and I thought I knew how much, but I was wrong... this route takes you through the really nice parts, which has the advantage for biking that it's not really on the driving route to anywhere, and pretty much traffic free.
It also goes right by Fry's and Know Knew Books on Cal Ave... something to keep in mind for next time!