If you're doing business and not using LinkedIn you are behind the times (for sure!). If you're using SalesForce and LinkedIn, syncing the data can be tough.
Here's a quick helper button/link you can add to SalesForce when you send a LinkedIn invitation out.
Clicking on this brings up a pre-filled completed task:
So let's create a custom button:
1st: Goto Setup -> Customize -> Leads -> Buttons, Links and Actions
Here's the code for the URL:
Save and then goto your Leads -> Page Layout and drop the new button in there. Enjoy and I hope this helps.