Rick walks us through SxS COM in VS, "An easy way to create Side by Side registrationless COM Manifests with Visual Studio"
"Here's something I didn't find out until today: You can use Visual Studio to easily create registrationless COM manifest files for you with just a couple of small steps. Registrationless COM lets you use COM component without them being registered in the registry. This means it's possible to deploy COM components along with another application using plain xcopy semantics. To be sure it's rarely quite that easy - you need to watch out for dependencies - but if you know you have COM components that are light weight and have no or known dependencies it's easy to get everything into a single folder and off you go.
Registrationless COM works via manifest files which carry the same name as the executable plus a .manifest extension (ie. yourapp.exe.manifest)
Besides the fact that Rick uses Foxpro in his walk-though (if you know his past with it, his using it makes sense, but I still found it funny) his article showed me a solution to something that's been vexing me for a while (and now in hindsight I feel kind of stupid in not knowing...), related to the manifests. Also I'd briefly tried using SxS COM once, but when it didn't work as expected for me I took the easy, old style, route. Now I see where I went wrong (and am glad Rick shared his knowledge and experience!)
Anyway, if you live in a cross COM <> .Net Dev world, this article might come in handy. I mean think about deploying your COM components with your .Net app an never warring about regsvr32'ering them!