People mean different things when they say "local storage". Some of the storage APIs prompt the user, some don't, some only prompt if you ask for more than a certain amount of storage space. The various browsers are not consistent, especially when it comes to quota management.

I wrote up some notes on this, though they're about a year old now and the browser UIs continue to evolve: http://tech-blog.clericare.com/2012/02/choosing-right-browse...

For someone building a consumer web app that needs to painlessly convert users in volume, I can see where it would still be a pain. For me, it's not so bad -- my app is B2B, and having an install step as simple as clicking "Allow this app to use up to 500MB on your computer?" is actually a huge improvement over the "enterprise" junk we compete with.

What browser does this? I've never run in to it.