Question: I'd like to create a calendar for each item in an existing list. Aside from doing this manually, is there any batched way of doing this?

Update: I have a list of boardrooms with detailed information about the location, equipment available, contact info, etc., and I would like to attach a schedule (the calendars I'd like to create) to each of the boardrooms for booking purposes. I would then like to create a web part that allows working with each boardroom calendar.

Answer: 
Based on your updated requirements, multiple calendars aren't really necessary. You can use 1 calendar with additional metadata (like lookup columns to other lists) to pull off what you need. When users fill out a calendar item, they fill out the metadata. You can use this metadata to create additional views to slice the data to show bookings for a particular boardroom to show it's availability or what ever you'd need.
First of all - you can definitely do this using PowerShell. Question: Are you going to want future calendar lists to be automatically provisioned upon creation of an SP List Item? If so, there's a two step approach here - first, you'll need PowerShell code to create lists based on the current items. 

Second thing you'll need is some sort of automated means of creating new calendar lists when new list items are created. Depending on your version of SharePoint, you could perhaps customize your list with InfoPath - adding some logic to use a web service call to lists.asmx to provision a new list when a list item is added.