Off-bike strengthening of neck/shoulders for aero position

So here’s the situation: it’s been raining a lot up here, so I’ve been putting in fewer miles on my tri bike than would be ideal. (Rather be on road bars in nasty weather, and besides, your butt gets REALLY wet riding a Softride in the rain.) Additionally, I’ve just gotten a touch of runner’s knee, so my bike mileage may be a little limited in the near future. I’ve got a HIM coming up in September. My legs should be good to go, even though I’ll likely be a touch undertrained. My biggest concern, though, is neck and shoulder comfort for 56 miles.

My current setup is comfortable (enough) for Oly distance or a little longer - maybe a little above 30 miles. My last training ride on that bike for over 40 miles, though, left my neck and shoulders (esp. the right trapezius) tied up in knots for days. Under ordinary circumstances, I’d be inclined to address this issue simply by putting in more miles on that bike - last year I was able to stay more comfortable for longer distances, if I recall correctly. The knee issue may put some limits on this plan, though. Also, I really feel that my neck and shoulder strength is lagging behind my overall bike fitness this year.

So how best to work on this? Any good off-bike exercises to do? Should I take up amateur astronomy and spend hours looking straight up? And any suggestions on position tweaks that will ease the strain on the traps? (I vaguely remember reading something about arm rest spacing in relation to this.)

Thanks.

Mike Vick recommends this:

http://lh4.ggpht.com/_Mq5qyAsSNIQ/SXfZCyZFEhI/AAAAAAAAT8A/g8-R0VoEuAM/s400/pitbull-20.jpg

How about these for neck strength…seriously…all the wrestlers in college use to do these bridges. You could always start by using your hands/arms for support and you can do them this way or facing the ground:
http://www.oldtimestrongman.com/images15/wrestlers_bridge2.gif

I’ll have to look at your post again when I get home in a few hours. Internet filter at work is just giving me a red “x”, as usual.