...first, HUGE props to BryanC. Thanks for keeping the post-reply nonsense down--your list is awesome.
1. When did the pain begin? After my bike accident--hit by a pickup truck in late September of last year. I was in physical therapy and this helped/helps (I still do the exercises). I just started riding my bike again, and I have increased discomfort in the lower back.
2. What were you doing at the time? Or did the pain come on gradually over time? See above
3. Where, anatomically, is the pain? In the lower back, on the right side. It feels like it is just above the hip. It looked a little like what Q had posted, but instead of a vertical pain, it seems more horizontal (sacroiliac?). It starts to the side of the spine, not on it, and goes straight across the top of the hip.
4. What does the pain feel like? Sharp? Dull? Aching? Stabbing? Shooting? It is generally a dull, aching pain, but some movements (bending down and to the side, for example) cause a sharp, shooting pain.
5. Is the pain constant, or intermittent, or only on certain motions? It is a constant tightness/ache, but low grade. Again, some motions cause the pain to become more acute.
6. What motions make your pain worse? Sitting for long periods of time. Bending down, and particularly going to the right side. Took my first bike ride and
7. What, if anything, makes your pain better? Cobra pose

and also standing up and leaning back, to look at the ceiling. Ironically, running seems to help. The PT I was seeing explained that upright movements, like running, might relieve tension in that area.
8. Does your pain radiate to any other part of your body? Sometimes it radiates down my right leg, causing a tingling feeling. This can sometimes go all the way to my toes.
9. What things could you do before, that you cannot do now because of your injury? Bend over and to the right. Sit still in my seat for long periods of time. Be generally pain-free. Cycling without pain.
10. What is your main concern regarding the pain and its consequences? That I will have to limit cycling.
11. Have you ever injured that part of your body before? If so, how? No.
12. Is your pain getting worse over time? And if so, how much worse over what time period? It's too early to tell.