Size doesn't correlate to value, and often the smallest tools prove the most useful. Little things to bring along:
[1] A waterresistant notepad for jotting down data, thoughts, and prime locations come rain or shine. (Rite in the Rain Outdoor Journal, $5, www.riteintherain.com.)
[2] A 1:1 macro lens to get truly close up. (Pentax SMC P-D FA 100mm f/2.8 Macro lens, $540, www.pentaximaging.com.)
[3] A polarizing filter to turn blue skies bluer. (B+W 77mm Kaesemann Polarizer, $125, www.schneideroptics.com.)
[4] A headlamp for finding subjects-and your way- after dark. (Petzl Tikka Plus Headlamp, $35, www.petzl.com.)
[5] A camera remote to trigger your shutter without shake. (Sony Remote Commander for the Alpha 700 and Alpha 900, $27, www.sonystyle.com.)
[6] A light, full-movement tripod head to reach every angle. (Acratech Ultimate Ballhead with Quick Release Plate, $300, www.acratech.net.)
[7] Polarizing sunglasses to preview the effects of that polarizing filter. (Ray-Ban Cobalt Blue Clubmaster frame with Polarized lenses, $169, www.ray-ban.com.)