Five blue damselflies; find all differences! (or just look at them)

The azure damselfly (Coenagrion puella):

^{Olympus XZ-1, 112mm, ISO100, f5.6, 1/500s}

The white-legged damselfly (Platycnemis pennipes):

^{Olympus XZ-1, 112mm, ISO100, f5.6, 1/60s}

The blue-tailed damselfly (Ischnura elegans):

^{Olympus XZ-1, 28mm, ISO200, f8, 1/200s}

One of the Lestidae. It is more metallic, and its colour varies depending on the angle of the light:

^{Olympus XZ-1, 28mm, ISO100, f5.6, 1/125s}

The common blue damselfly (Enallagma cyathigerum):

^{Olympus XZ-1, 28mm, ISO250, f5.6, 1/100s}

There are more, but some I haven't been able to persuade to pose for me yet.

Can I tell them apart? Well, yes, back at home, from the photos, with a determination book. To complicate things further, the female versions have different colours, usually not blue.