In reply to Steve Putz:
Thanks for posting this. I was able to get my Windows 7 netbook to use the USB IR tower with Eclipse two years ago and just three weeks ago upgraded my desktop to Windows 7 and couldn't get it to work. Now I know why: the netbook uses 32-bit Windows 7 Starter and my desktop uses 64-bit.
I never would have thought of using a serial IR tower, but since seeing your post and by chance having a serial tower, now I've got it working in Eclipse with my 64-bit Windows 7! I still have three RCX bricks so this is perfect.
In case anyone needs some additional details, I bought a cable from Amazon:
"Plugable USB to RS-232 DB9 Serial Adapter (Prolific PL2302HX Chipset) (Sold by Plugable Technologies)"
It cost $11.95, the carton says "Windows 7 compatible" and came with a CD and instructions to run the CD before attaching the tower via the cable. IIRC, when I ran the CD it created COM9. I then ran the RIS 2.0 installation CD that came with the RCX and when it came to the part of finding the IR tower it automatically found COM9! It offered to download the LEGO firmware and downloaded it from my 64-bit Win 7 box. Very encouraging to see that happen.
I downloaded and unzipped the leJOS Eclipse RCX plugin to the Eclipse\plugins folder, restarted Eclipse, and the leJOS plugin appeared. In the configuration pane it only offered COM1, COM2, COM3, and COM4, so I had to use Windows Device Mangager to rename COM9 to COM1. But then Wow! I was able to download the RCX leJOS 3.0 firmware to the RCX right from Eclipse. Very nice. I keep a separate Eclipse workspace for RCX projects and have the full Eclipse experience available for programming the RCX and downloading via the serial IR tower.
Looking forward to seeing you again at the 2012 Bricks By the Bay convention in a few months. Thanks again for the tip about the serial tower.