i also keep most of my btc secured in an encrypted wallet.dat. still i would like to put a few somewhere for easy spending.

nevertheless, there are a lot of people who might switch from paypal to bitcoin, not with their entire wealth but with some digital pocket money. thats why "there will be web applications", there simply is demand. my point is more about WHEN there is a useable and "trustable" service, because the first jump from techs to no-techs seems to happen right now. so having a solid web application may speed things up, instead of risking the image of an unusable-payment-something given by the media.
just can't wait to see bitcoin break through

for a service to be "trustable" their should at least be the name of a real person. instawallet made a good start i think. its also nice, to give out a few bitcent to people just to try out.
as far as i understand instawallet, it is secured by the hash of the hind part of the url. like if i use 20 signs, it is as secured as some sign-up/login-system with a 8 sign username and 12 sign passphrase. please correct me