Browsers should be smarter -- allow you to write Post-its on web pages and remember them when you return. For instance, there are two similar products I'm considering purchasing that I've placed in my Shopping Cart. I'd like to write a memo to myself about what's different between the two, so that when I come back I won't have to scratch my head and waste the time to re-figure out the minor feature differences between the two.
Also, when I quit my browser (or worse, when it unexpectedly quits), why do I lose all the sites I was browsing? Why can't the browser remember which sites I was viewing and in which tabs, and pull them back up? If I'm in the middle of reading two articles and I accidentally quit my browser, there's no way for my browser to remember where I was let me pick up where I left off. How hard would that be? (This would also be useful for keeping my Ta-Da lists open all the time, regardless of whether I restart my browser.)