Since Andy and I discussed this, and I am the OP, I'll jump in.
I am currently running a few Zaps, mostly around making things happen in Quickbooks online, entering Sales Receipts either from a form entry or an e-commerce order. My other CRM then syncs these from QBO.
There are probably about a thousand triggers and as many actions now that Zapier supports some 250 apps. Web form to CRM is kind of obvious, but, at this point imagination is the limitation. Sending SMS messages, adding projects or tasks, based on activity in X2 or setting leadscores or activities based on activity outside of X2.
We just need the code and a reasonable set of triggers and actions.
If you have any ideas, especially for X2 trigger events (New Lead, Lead Converted, Opportunity Closed Won, etc.), or X2 actions (Create New Lead, Convert Lead, etc.) now would be the time to chime in.