1-800-FREE-411
Free411 offers free nationwide directory assistance for busisness, government, and residential listings. Yes, free. The service is supported by short advertisments (around 12 seconds). Most ads are related to your directory request. For example, if you ask for a Dominoes listing, you might hear a Pappa Johns ad. There are some exceptions, you may have to listen to an ad before being connected to an operater. On the whole, the service runs fast and smooth. If the automated operator cannot fulfill/understand your request, a human operator is on the line right away. There is an added bonus at the end. You can have the number you requested text messaged to your phone. Free411 does not charge any additional fee for this service, however, your carrier's SMS charges still apply. Free411 also offers free directory assistance through its website, so check 'em out.

1-800-411-SAVE
411Save is another great free directory assistance provider. Like Free411, 411Save is supported by advertisements (10-15 seconds). At this time 411Save only provides business listings, but the service is quick and easy and promptly connects you with a human operator if there is trouble with the automated system. Users also have the option to recieve their listing via text message at no additional charge. 411Save gives consumers a superior alternative to the major carriers' directory assistance services.

Google SMS
Have you ever wanted to "call" Google? Now you can. What's better is that they'll even answer you...for free. Instead of calling a toll-free directory assistance number, try asking Google for a listing via SMS (text messaging). There is no fee, however, you will be charged for each text message by your carrier (usually no more than $0.10-$0.15 per message depending on your plan). You don't need a phone-based Web browser, or an Internet subscription package, just text messaging capability.

Here's an example of how it works. Create a new text message and enter "46645" (the numeric equivelant of GOOGL) as the number you will send to. In the text area add: "pizza 92103"
Within a few seconds, you will receive 2 text messages (depending on the number of results). The first:

Bronx Pizza Inc
111 Washington St
San Diego, 92103
619-291-3341

Papa John's Pizza: Hillcrest-Uptown
1280 University Ave
San Diego, 92103

Google SMS allows you to search pretty much anything in a directory listing plus a lot more. Search for stores: best buy san diego. People: jerry sanders san diego ca. Find movie showtimes: braveheart 92101. Get directions: from petco park to 3100 fifth san diego. And sports scores: pittsburgh steelers. 

Google will provide directory assistance services for non-smartphones by sending a text message to GOOGLE (466453) with the name and location of the business they want and get a text back in response. Gmail also has new phone-calling features built in, and smartphone owners can get a free voice search applications from Google via Google Mobile.  But it is ending its free directory assistance at 800-GOOG-411 in November 2010.

For more information, see the Google SMS guide. Also visit SMS 411. It is a good site with lots of tips and tricks for Google SMS and text messaging in general. If you are new to text messaging then this site is a must.