Editor's note: a number of these tools are changed or no longer available.

Google: How To Submit to Google Webmaster Tools

Submit your site to Google's search engine via Google Webmaster Tools

Find instructions at Using Webmaster Tools

Bing: How To Submit Your Website To Microsoft's Bing

Bing (was MSN Search) is Microsoft's new search engine service.  Their  WebCrawler, MSNbot, will index your site.

bing.com

Are Web apps and services heading to extinction? Mobile applications can embed common web functionality and interfaces--or--within commonly used apps, such as e-mail?

Specifically, web-based apps like Twitter have new competition in apps, which integrate micro-blogging directly into your e-mail.

Another example would be the many web-based calendar and event services. These independent web apps have their own interfaces.