Like a lot of people, I pretty much run my life on the Web these days. I use online bill pay, I shop at Internet retailers, I keep in touch with friends electronically, &c. I'm pretty comfortable with the standard home computer security setup for that stuff: physical router, antivirus suite, strong passwords, that sort of thing.
Are smartphones at least as secure at storing sensitive data as a home computer with that standard protection level? I'm thinking of stuff like credit card numbers, passwords, financial information and health records. I don't know if something about their architecture or the fact that they're on cell networks makes them less safe.
In particular, I always look for the green HTTPS indicator in my browser when I need to do something secure-ish on my computer, but I have no idea how apps store the data I punch in, or how to tell whether they use secure/encrypted transmission techniques. I end up not doing anything with my phone that involves money or passwords, which means I'm missing out on a lot of the benefits of what is really a cutting-edge piece of technology.
The best resource I've been able to find so far is Android Guy Weekly: Is Cellular More Secure than WiFi?, which points out some differences between cell and wi-fi systems but doesn't give much advice about what to do about them.
If it helps, assume for simplicity's sake that the phones in question connect to the outside world (i.e. the Internet) via cell only, not wi-fi or Bluetooth or anything else.
Edit:
In retrospect, I should have asked two separate questions: "are cell networks as safe as wi-fi," and "are smartphones/tablets as safe as desktops/laptops." I guess it's too late to try to separate the two now. At least it looks like the former question has sorta-kinda been brought up on this site before, though with mixed results.