Before releasing your site to the world, take some time to view your website from many different angles. Try computers that are connected at 14.4 and 28.8 to see how fast it really is. Viewing your site in-house from a hard disk will mask errors that other users may be experiencing.
In addition to different connection speeds, try your site in different browsers, including Microsoft Explorer, Mozilla Firefox, Google Chrome, among others. Also, try your site with different screen resolutions. Most of your viewers will be using 800×600 for their desktop. After all of these tests, is your website as fast as you think it is?