Yeah, the back button thing is a long-standing hate of mine. Opera manages to work around this by just caching the pages. When you go back, it opens the page from the cache. Perhaps in a small number of cases this is somehow wrong and you need to refresh (in which case, the 'Refresh' button usually does the trick) but 99% of the time, this just works, is useful, and lets you usefully look back at data in, for example, multipage sign up/purchase forms without having to continually repost.
It completely baffles me that the other major browsers don't do this.