At Ubuntu Unleashed you can find a document about different settings to optimize startup times of the system and applications itself.
The noatime and nodiratime settings are unneccessary in Hardy as the default option relatime only updates the access time if the file has been modified after the last access timestamp.
You can enable the full power of the upstart manager by enabling multi-threading. In /etc/init.d/rc at line 24, set CONCURRENCY=shell. But beware of slight problems upon booting. Some services might
be started before depending services are. Also some lines upon startup are printed twice. If you have problems getting your machine up and running, change it back to none.
Another nice feature is adding the profile option to the kernel line upon boot. The bootup will take longer than usual but the readahead-daemon will catalog all needed files and on the next boot (without that parameter), all needed files will be preloaded before boot.
On Desktops with much RAM, the preload daemon also speeds up working.