There are several online services offering "Internet Call Waiting" which is a service that you subscribe to and pay a monthly fee to have, which also requires special services from the phone company to make work. Now you can own a device that will do it for you WITHOUT subscription fees! Additionally you dont need special "call forwarding on busy" services to use it. You simply need call waiting, and optionally call waiting/callerID. You can now own the device for less than $25!

Catch-a-Call is a small device which can be used in conjunction with STANDARD call-waiting/caller-id You simply connect your computer through it as well as a telephone and you get onscreen information of the person trying to call you, WITHOUT addiditional fees for this "special" service. I have seen these devices sell on eBay for under $10! There are several different units ranging from very basic to feature-full. Please check the manufacturer's website for the unit that fits your needs!

 

                         

                

Get Calls While Online 

and 

See The Caller's ID On-Screen

 

 

When a call is received, a box appears on your computer screen and displays the caller's information as well as date and time.

You can answer the call or choose to ignore it. Or, you can click on the name and block the caller from interrupting you again.

    

  • Get phone calls while online—using your existing line. 
  • See the Caller's Name, Number and Date and Time.
  • Records all data for future use.
  • CallBlock(tm) allows you to stop the callers from interrupting you again.
  • Rings when a call (or fax) is incoming.
  • Holds the internet connection 10-25 seconds.
  • Will not affect the computer speed.
  • Simple connections.
  • Connect to your phone, Modem and wall jacks—and go !  
  • Totally automatic operation.  
  • Compatible with Voicemail.
  • Works with all computers and operating systems. (ID function available for PC only).
  • Fully compatible with Distinctive Ringing Service.  Patent
  • Caller-ID compatible; Works with your existing caller ID box.
  • Small, attractive unit.  
  • Can also receive Faxes while online.
  •  Works with and requires Call Waiting for online operation. 
  • Optional Online Caller ID function requires phone company Call-Waiting-ID service

 

 

More info here!