Teammate in college lost a spike in an indoor 800m somewhere in the first 200-300. He finished the race, but his foot was so chewed up from running barefoot on the mondo that he had to crosstrain for a week while it healed. Looked pretty much like the picture Rowbury posted.
Luckily it was just coming into the end of his season, so it wasn't a huge loss fitness-wise. Was able to finish out the season on a good note.