You can access the internet from any of the following locations in Liberty City.
-Any of the TW@ internet lounges -On the laptop in one of your later safehouses
Any website you hear on the radio or see posted on a billboard, you can visit it. Most of the websites are just for a few laughs, but a few of them actually have a purpose.
You can set up dates with people on love-meet.net, order cars, or buy ringtones/wallpapers for your cellphone. Your email is also frequently used for staying in touch with story characters and getting mission details sometimes. Brucie will also send you emails asking you to steal a certain vehicle for him.