Ever have one of those moments where you wanted to leave someone a message without actually talking to them? Understanding this feeling, MobileSphere recently introduced Slydial, a free service that allows users to leave a voicemail for a person without risking that they answer the phone.

Those wanting to avoid an actual conversation simply need to dial 267-SLYDIAL (267-759-3425), sit through a brief history about Slydial and why it should be used, an advertisement that will last a couple of seconds, and then enter the person's phone number. Once all that is completed, the Slydial service connects to the person's voicemail just like a regular phone call.

A brief test indicated it works with Verizon Wireless, AT&T and Sprint Nextel, and each test call carried out by BetaNews took less than two minutes total. MobileSphere said Slydial should be able to work on all wireless phone carriers operating in the United States.

However, Slydial wasn't designed to leave voicemails for landlines, and it also cannot leave voicemails on prepaid mobile phones, regardless of phone carrier.

Using slydial may seem impersonal and could be abused by a small minority of users, but it's a more-personal alternative to sending a text message. It's been possible to return a voicemail after one has been left for you, but Slydial is the first service that lets you send a voicemail first.

Although the service is free to use, there are several different options available for those who want to remove the advertisements. Users can pay $0.15 each time a call is made to the service, $4.95 per month, or $29.95 for a one-year fee.

Creating a free MYslydial account can simplify the service for those who want to frequently leave voicemails for the same number. The account can store contact information and let the user dial by name, or create a pin number that can be entered as a shortcut.

Slydial first rolled out in March, with about 5,000 users signed up since then. Today's launch marks the public beta test.

In order to entice users to pay, MobileSphere has limited free Slydial voicemails to 90 seconds in length. The company also has intentions to offer its technology to telephone marketers. Slydial is built upon MobileSphere's VMS 2.0 platform, which can also be used by marketing companies and advertisers who are interested in using in-call ads to reach new markets.

So while you may initially receive a break-up voicemail from a significant other afraid to speak in person, your next voicemail may be an advertisement from a MobileSphere partner.

UPDATE: MobileSphere contacted BetaNews to clarify that it won't have advertisers leave voicemails directly. The only ad that currently plays is the one before the recipients phone number is entered, the company said.