I'm sure I read somewhere that there are 3 kinds of chives, regular, garlic and leek. But Ican't remember the source of the information.

I have two of the three here. The regular which are now dieing out and only producing the seed heads, and the garlic chive (also known as garlic grass), which is still nice and green and not producing the flower heads yet.

Sure sounds like chives rather than leeks. I accidentally planted 15-20 leeks in a clump last year and they overwintered but haven't spread out or done much this year. I also have regular and garlic chives - the regular ones are in flower exactly as you describe your "leeks" and the garlic ones are a bit shorter and not yet in flower. I also looked and the clumped leeks that I have still have flat leaves while the chives are more rounded and hollow.

I think you're right, makalu. I'm pretty sure these are chives. Thanks for your responses, all!