It's hard to keep track of all the new services from Google Inc. (NASDAQ: GOOG). But one of the latest offerings is free 411 directory assistance (DA) – which you can dial at 1-800-GOOG-411. It's pretty cool stuff and I'm sure lots of people are giving it a try.

But why is Google going into this old-time business?

I had a chance to talk to Dipanshu Sharma, who is the founder and CTO of V-ENABLE. His company provides voice-activated search and even 411 services. He was formerly with Nokia Corp. (NYSE: NOK) and has several patents to his name.

Here's his take:

Why the interest in DA? How big do you see this market?

DA was a $9.4 billion market last year (according to the Kelsey Group) and is set to grow to $13 billion. Local advertising is the big play here. So far directory assistance has been a paid service where users shell out $1.50-$1.79 per call. This is changing fast with new ad supported services essentially making this free.

What's your impression of Google's offering so far? You think Yahoo Inc. (NASDAQ: YHOO) will jump into the fray?

Google has been playing with a free service for a while. Their offering is fully automated (i.e. it has no human operator backup). This is in contrast to 800-FREE411, which has been around for two years and has human operators.

I feel operator backup is essential on FREE-DA services as the users want to be able to save money without getting frustrated with the user experience. Goog-411 has not gotten good reviews so far. I think it's too geeky right now. Hopefully they will make it more user friendly over time.

Yahoo is making its moves by hiring top Tellme execs. If Yahoo is serious about advertising and they have to be in the DA business.

What about mobile DA? What's the attraction of that market?

The ultimate user interface for DA is one that lets users ask their request and show value-added services on a phone screen, such as sponsored listings, maps and directions. Mobile DA is that product. V-Enable announced its mobile DA product at CTIA last month and even won the best wireless software award (by Laptop mag). The key attraction is the potential of the local advertising market.

Local search has been around for some time now, but DA clearly is the way people ask for information when they are mobile. So now search companies are working to integrate 411 with the local advertising. Carriers on the other hand should feel threatened as their cash cow 411 business could be free in the next 24 months.

Tom Taulli is the author of various books, including the Complete M&A Handbook and the EDGAR-Online Guide to Decoding Financial Statements.