Thanks, Oliver. There is a customer map already - go to Customers in the main menu and choose the Customer map tab, but it doesn’t show leads.
We’ll keep this feature request open for adding a map of your leads.
You might also find Customer and lead mapping and visit (field sales) route optimisation would be useful. It’s not built yet, but I thought it worth mentioning in case you’d find it useful and want to give it a vote. Cheers.