No really...
Up until today my iPhone 3G has been running like a dog - it crashes Safari every other time I try to load a web page, and it frequently can't even open Mail without crashing. Even when it succeeds it hangs for >30s (to free memory?) before allowing scrolling *every* *single* *time* I use it. Completely frustratingly unusable. As I said above it seems to be fixed now with 4.0.1...