Hi

I am currently pulling down a Users tasks using the API.
I would like to show the user details about what this task belongs to.

Now the Task contains a field called 'WhatId' which is the Id of that which the task is related to.
Now i would like to query information from that object with the 'WhatId' but i don't know which object to query.

Salesforce has a great machanism where the salesforce url followed by an Id will bring up any object type.
How is this done and can i do this through the Api?
From a given Id, determine which object this Id belongs to

Thanks and Kind Regards

GrantM