The Internet has made it easier than ever to find an obituary, whether it is an obit for someone who died recently or someone who passed away years ago. While some websites will charge a fee or ask you to register, often you can find an obituary for free.
Use the Social Security Death Index, which has information on most deaths that have occurred in the United States since the 1960s. You can search the SSDI through Ancestry.com. The interface allows you to search by name, birth date, death date, keyword or other event dates. Ancestry.com asks you to register to see death records.
Visit ObitsArchive.com, which has a fast search function. It is especially useful for searching for recent obituaries from the past 10 to 15 years, although its database extends beyond that time. Searching here is free, and will return names, dates and publications. To pull up the full obituary, you must register.
Search for obituaries at NewspaperArchive.com. For historical research on obituaries, general genealogical work or historical research of any kind, NewspaperArchive offers an extensive database of articles. Search the site by the deceased's name or by keywords. It's a subscription service, but reasonably priced.
Search daily newspapers for recent obituaries at Obituaries.com. The website offers an extensive, but not complete, list of American and Canadian newspapers with links to the papers' obit pages. Additionally, it has a search function that allows you to search newspaper sites that are affiliated with Ancestry.com.
Visit the National Obituary Archive website. Despite its imposing title, this is a hit-or-miss collection. Start by searching for the hometown of the deceased. This returns a long list of matches. Use the advanced search function on the results page to narrow the search by name and approximate date of death.