Here's a picture of the silver-spotted skipper (Epargyreus clarus) that I found feeding among lupine near Altamont, Utah this last June. It is a large species, as skippers go, and quite attractive. It occurs throughout the western US and feeds on a number of legumes.
The second picture shows it feeding in flight - sliding its long proboscis into the uneven curves of a cupped-shaped hypanthium. This is quite impressive if you stop to think about it: a relatively heavy insect holding itself in midair and twisting its slender mouthparts through an undulating tunnel to get nectar. Nature seems to know what she's doing.