As mentioned in this question, inventory size is an issue in Diablo II. So far, I don't plan on playing with others, so for me loot whoring is not an issue.
Given this, I am interested to know if dropped loot ever despawns and if so under what circumstances. In other words, if I've got a book of Town Portal scrolls can I just keep loot running over and over until I've picked up and sold all of the dropped loot? If I'm playing solo - is inventory size really an issue, or just more of an inconvenience?