If you haven't noticed or browsed through your profile settings, you probably won't know that you are able to hide signatures from showing up, thus making pages load faster, about 200% times actually.

Since we do not have a signature rule as of yet, there are some signatures that are pretty large and may slow your surfing if you are on a slower connection such as dial up. If you disable this option, you will be able to browse a lot more faster.

You can also disable avatars as well, but I believe enabling the avatars will be able to help out identifying people, as I'm sure most identify people online by their avatar rather than remembering their username.

There are other options, such as disabling smiley images, images in posts overall and disabling the word censor.

These options will come into effect once you login to your account. If you logout, your settings will not work.

Options page:
ucp.php?i=prefs&mode=view
Under board preferences -> Display options