Share point 2007 provide great functionality of work flows using share point designer. Sharepoint designer workflow provides different set of workflow activities to support users in designing their custom workflow. However designing is not limited to out of the box activities but it also provides power to create custom designer activities so that user can design their own logic according to their business.
In my case I was just thinking that if we can call a webservice from a sharepoint designer it would make a life easy for doing lots of things can can only be achieved by complex calculation from external systems.
There are two ways for this
1. Write your own custom activity
2. Use an extension from codeplex
I found following extension package very help full
and not only this but the deployment is fairly simple and help provided on following blog is also great.
Using this in conjunction with my SPD workflow it makes my life easy and I managed to call my webservice from SPD workflows with in 15 minutes (Installation and configuration ) :)