The whole binational capability offered by being close to the border is also a pretty neat opportunity/advantage that I feel a lot of startup companies could utilize well if they wanted to, since there are a lot of highly educated and intelligent folks on the other side of the border.
For myself, living about two hours East of San Diego (in Imperial County) we have a lot of the same advantages from this perspective (since we share the border with Baja California's capital, Mexicali, where there's a strong manufacturing presence and lots of highly educated individuals) but we have 0 tech companies on the US side (and high unemployment to boot). Compared to San Diego, our locale isn't as desirable (we get high temperatures during the summer, hitting the 110+ degrees Fahrenheit mark, and the closest beaches are in San Diego) but we have plenty of sunny days and lots of open spaces (while I don't partake in it, there's lot of people that come down from San Diego and other places to go ride their dune buggies and stuff out in the desert and places like Glamis), less expensive housing and nice small schools/communities to raise a family.
It would be really cool to see some tech companies seek us out too, if they had employees that liked Imperial County's advantages, and setup shop down here (it would be great for the community and could start a greater influx of tech companies and/or an enhanced relationship with other tech hubs in San Diego/Bay Area).