If you have a nice new laptop with only an HDMI output, and a rather old monitor with only a VGA input, then I’ve got some good news. I’ve just discovered that you can now get an adapter (like the one above) which for a lot less than the iPad one (like around 15 quid) will convert your twenty first century digital output into twentieth century analogue signals. This is particularly useful if you work somewhere where every lecture theatre has VGA connections for laptops. Like The University of Hull. The adapter I got was from a UK seller with good feedback, you can get them directly from China for even less.
Important Note: There are a lot of people selling HDIM to VGA cables that purport to connect HDMI and VGA systems together. These will not work. The kind of thing you want must have a built in chip that performs the digital to analogue conversion. Make sure that the thing you buy looks like the picture above (with quite a big lump on the VGA socket) and look for phrases like “with chip” and discussions of which video modes are supported in the description.