Hi Sunil,
Though this post is quite old, thought I'd give it a try.
I have a similar requirement to create an OAuth mashup webservice for yammer.
Though I am not very sure what to enter in the URL fields, I did try to enter some authentication data.
I have to use this mashup webservice in a data mashup. But when I create a data mashup, I couldn't find the webservice I created in the REST webservices. Not sure if this is possible or not.
Did you manage to achieve this with Twitter? If not in a data mashup, is there any other way I could trigger this mashup webservice. Any kind of information would definitely be helpful.
Thanks and Regards,
Sumeet Narang