I posted such a byte buffer class a while back.

Works fine for me, no bugs found since the version I'd posted though feedback is always welcome. I need a tool like this I can trust and though I have a "test suite" to exercise as many things it does as possible you can never be too sure.

BasicBuffer, Binary Stream Class

Works great for things like stream assembly in Winsock control DataArrival event handlers. It has a few "extras" in it for this application to help with protocols where you have a leading Integer or Long "length" header. For Winsock applications it works for output as well, giving you a lightweight way to prefix the length onto an outgoing payload so you can use one .SendData call to blast it out. Handy to avoid extra SendComplete events that might otherwise throw you off.