Apparently, web apps may not be quite the cure-all that everyone thought they were. The linked article gives five reasons why a browser-based app may not be the best idea.

Here's five of my own, related to cell phone web apps.

• A website doesn't know where you are. Even the most basic phone can tell what country its in - but the most advanced website can only guess.
• Bandwidth is not free. It is both quicker and cheaper to perform simple actions (like drawing graphs) on device rather than incurring a round-trip to a server.
• C is not dead. Despite what Java aficionados may like to think, C-based languages still have a place in the world of embedded software, particularly where performance critical applications are concerned. On a cell-phone, just about everything is performance critical.
• Write Once, Run Anywhere doesn't work. You will have just as many platform bugs if you use web-based technologies - and they will be harder to find, not easier.
• A secret known to two people is no secret. If my private data is sat on my phone, then you pretty much have to get the phone out of my hands to get at my secrets. If however, the data is all on a website somewhere, then the number of potential vulnerabilities just sky rocketed.

And one final thought. Ebay, Facebook, and Google Maps all started as web apps, and now have cell phone clients.