We've all been there before. You need to return a call or deliver some bad news, but for whatever reason you don't want to speak with the person on the other end of the line. Sure, you could shoot off a quick e-mail or text message, but that's just not the same as a phone call.

Now, thanks to a new, free service called Slydial you can place a call from any US mobile or landline phone to any other US cellular number and be routed directly to voice mail. The only catch is that you'll have to listen to a short audio advertisement-most are about 30 seconds long-each time you call, pay 15 cents each time to skip them or become a paid member.

"Pretty sly, huh?" a recorded voice says playfully when you call Slydial, which is currently in a public beta, or test, release.

Though the ability to avoid a conversation and leave voice messages on someone's mobile phone isn't new-many wireless carriers and other phone service providers offer the feature, but it can typically only be used within one cellular network or geographic area-Slydial lets users call any US mobile phone number regardless of the carrier or location.

There are a few ways you can use Slydial. The easiest method is to simply dial 267.SLY.DIAL (267.759.3425) and then plug in the phone number of the person for whom you want to leave a voice message. (BlackBerry users should remember to hold down the "Shift" key when dialing letters within phone numbers or simply use all numerals.) After dialing the digits, you'll hear an audio ad and will then be connected to that person's voice mail.

You can also set up an account at Slydial.com that's associated with your phone number and enter in the contact information for folks you think you may want to Slydial, giving them each a specific nickname. Then whenever you call the service you need only dial the first four digits of nicknames, followed by the pound sign (#), so you don't need to remember actual phone numbers.

And finally, you can employ the service via the Web by logging into your account and clicking the icon that appears next to your contacts. A few seconds later, your phone will ring and you'll be connected to Slydial and then your contact's voice mail after picking it up and listening to the ad.

t's sly, I'll say that, but not perfect. Depending on the phone being used and the service provider, call recipients may not see a missed-call icon or a record in their call logs after receiving a message from Slydial users-a dead giveaway that the caller skipped directly to voice mail. The caller ID function needs to be activated on users' phones for Slydial to work. And it's currently available only in the United States and may not work for people with pre-paid mobile phones, according to the Associated Press.

As mentioned above, the basic membership is free, and you can choose to pay 15 cents a call to skip advertisements. There are also two tiers of premium membership: the monthly version that costs US$4.95; and the US$29.95 yearly subscription.

So far, there are about 5,000 registered Slydial users, the AP says.

Surf on over to Slydial.com, or plug in the digits on your mobile to give it a try. You'll be glad you did next time you need to call in sick, but don't want the boss asking too many questions...