Originally Posted by
cyccommute
You got them there

Two minutes isn't a lot of time. And if the flat is on the front wheel, you couldn't even pick up the bike and spin the wheel so that you could get light.
Really? Is this your ultimate argument against a dynamo light? Is it really THAT much better for any light mounted on your bike?
I got a flat with my handlebar mounted removable LED once (an all in one, not with external battery pack). Yes, I could easily remove it to use for lightning while I changed my tube, but I couldn't easily hold it while using both hands for the job. If it was a light with an external battery it would have been even harder to manage as it would have been too parts to deal with.
In the end this is one of the many reasons I decided to get a helmet mounted light as a secondary headlight.