Thanks for all the ideas.
You would think that one of these tent companies would make something for us cyclist. So that we could park our bikes inside the vestibule.
http://www.mountainhardwear.com/Ghisallo-1/OU9469,default,pd.html
I took one of these for a 2 month tour of Europe and let me tell you, it was the best thing ever. 1) You don't need to lock your bike in camp, it's right in the tent with you. Out of sight, out of mind - people don't even know you have a bike (unless it's your camping neighbor that sees you stash your bike into the tent) 2) Dry as a bone in the worst weather. No need for saddle covers, etc. 3) Like people have said, keep your bike in sight at all times, there's something very very comforting knowing that it's in visible range even when you're zipped up tight in your tent
Even when you need to run to the shower I felt fine with it stashed out of sight - I was more worried about my bags getting jacked than the bike.
It only weights 2.75 lbs, it's easy to set up and easy to clean out (pick it up and shake the dirt out). Vestible is big enough to stash all your bags no problem. It doesn't have a lot of room in there if you're a big guy or like a big tent. On the up side the ground cover doesn't need to be big.
Every morning I'd get my shammie out and wipe all the dew off the outside of the tent, wait a bit for it to dry out, and it breaks down in a few minutes and into the stuff sack. I love that tent!
One more trick I used is to wrap a good strong velcro strip around the rear wheel and another around the brake, like a parking brake. This kept the bike from rolling in case you're on an incline and if someone did try to take the bike there's going to be at least a minute of confusion while they try to figure out why the bike won't move, get off, find the velcro and pull it off, etc. It's the cheap man's super lightweight stealth short-term lock
We had one bike stolen (out of two locked together) right outside our hotel room in London England at the tail end of our 2 month trip. We had a pretty substantial cable lock but they cut it clean through. Big cities need full lock protocol against professional thieves, as previously discussed, no doubt about it. By some miracle we didn't get our bikes jacked in Amsterdam, looking back at it.