Create a field highlighting next activity

Hello All,

I'm looking to create a field in the opportunities module that showcases or highlights the next activity (call, meeting, task, email, etc.) so we can see what our next step with an opportunity is. These next steps need to also correlate to the contacts or account assigned to the opportunity. I found a workflow that tells you what the LAST activity was but I'm not sure how to modify that to tell us what the NEXT activity is. 

Any help is greatly appreciated.