broad-faced sac spider (Trachelas sp.) - Montezuma, Costa Rica

Mariposario Montezuma Gardens

sternum

endites and fangs

tarsal claw tuft

Epigyne

running crab spider (Philodromus spectabilis) - Olympia, WA

Grass Lake Park, Olympia, WA - 5mm

pedipalp

non-native invasive spider (Cithaeron praedonius) - Winter Springs, FL

Thanks to /u/neuralphreak for an outstanding job of collection/curation.
Winter Springs, FL, 17 Jan 2013

This spider has translucent patches on her legs, a dark spot behind her anteromedial eyes, and featherlike hairs on her legs. Her tarsi end in long, tentacular pseudosegments, which can grasp projections in the environment and pull the spider around. Her native range is vast, from Tripoli to Taman Negara, and she readily thrives in urban environments, eating the pests that thrive in filth. Like Indo-European languages, she has become established in Brazil, Florida, and Australia.

She has some kind of caked gel on her mouth-hairs

Note the pigment dot behind the AME, and the evident roundness of those eyes.

Epigynum 

Clarified epigynum

Translucent femur and pseudosegmented tarsus 

mite (unknown) - Olympia, WA

Capital Campus, Olympia, WA

toe-winged beetle (Ptilodactylidae) - Montezuma, Costa Rica

Mariposario Montezuma Gardens, Costa Rica

ID thanks to /u/masterswordsman

caddisfly larva - Olympia, WA

Grass Lake Park, Olympia

shining fungus beetle (Scaphidiinae) - Montezuma, Costa Rica

Mariposario Montezuma Gardens, CR

ID thanks to /u/Joseph_P_Brenner

bee (Lasioglossum titusi) - The Palouse, ID

Latah County Bee

Metasoma I noticeably more punctate and metallic than M2

Area between lateral ocellus and median eye margin noticeably smoother and less punctate than frons

Mesoscutellum sparsely punctate with large and small punctures