Back when I first posted this article, hotels were few and far between that offered wifi of any sort in the rooms. Today, it's very likely that your hotel will have an internet connection available you can access from your room--or at least from the public areas. Thus there are fewer options for internet outside of hotels, unless you take the second option, the Venezia Unica Card, explained below.
Another way to get internet services all over Venice is through an add-on to the Venezia Unica card, which allows you to access the access the Venezia Unica Wi-Fi network. Also see how to use all the services the card offers.
Here are a couple of suggestions for internet cafes and internet points in Venice. Most are in convenient locations not far from the train station.
Via cappuccina,153/A -- by the train station
Near the Realto Bridge
A Reader's Recommendation for an Internet Cafe in Venice
One of my challenges was finding a "good" internet cafe in Venice. The concept of bringing your own laptop and connecting was very foreign to folks there (while it was the norm in Florence... go figure). I did find one internet cafe 50 feet off the main drag in Venice by the train station that was nice, clean, quiet, and allowed laptop hookups. They also would burn flash card photos to CD and other services. I was quite happy with them, so I wanted to pass them along.
Website: abc Color
Other Venice Travel Information
Venice Travel Guide: A compendium of useful information for visiting Venice. Look here first.
Venice Hotels: Most have internet.
Venice Travel Guide and Directory
Links to the most informative web pages on Venice, Italy.