Many journals now provide access to their 'table of contents' via RSS feeds. Table of contents can be read using the popular Google Reader. The steps are: setup a Google Reader account and then on journal sites such as:

• Nature
• Science
• Scientific American
• New Scientist

Click on the RSS feed icon and choose Google Reader as your feed reader.

Check the Library's 'How-to' guide on 'Alerting, Services, RSS Feeds & Email'