I think lifting weights is a favorite but secret past time. +5

not all can, some species have "suckers" on their feet

They have suction pads under their feet. The attatch their feet to any surface any by using their suction pads create a vacuum beneath their feet. This way they can cling to any suface. Even ordinary lizards use the same suction pads to climb up walls or walk on the ceilings.

I had a lot of geckos in my young days. They would be on the walls, ceilings, where ever with funny sucker feet. sticks to anything. I think that's were they got the idea for velcro. lol

1) "Seta (plural: setae) is a biological term derived from the Latin word for "bristle". It refers to a number of different bristle- or hair-like structures on living organisms. Animal setae: In zoology, most "setae" occur in invertebrates. Setae in annelids are stiff bristles present on the body. They help for example earthworms to attach to the surface and prevent backsliding during peristaltic motion. These hairs are what make it difficult to pull a worm straight from the ground. Setae in oligochaetes (a group including earthworms) are largely composed of chitin. Setae on the legs of krill and other small crustaceans help them to gather phytoplankton. Setae in entomology are often called hairs. They are unicellular and formed by the outgrowth of a single epidermal cell (trichogen). They are generally hollow and project through a secondary or accessory (tormogen) cell as it develops. The setal membrane is not cuticularized and movement is possible. Serve to protect the body. Setae on gecko footpads are small hair-like processes responsible for the animal's ability to cling to vertical surfaces. Plant setae: In botany, "seta" refers to the stalk supporting the capsule of a moss, hornwort or liverwort, and supplying it with nutrients. The seta has a short foot embedded in the gametophyte from which it grows. Setae are not present in all mosses, but in some species they may reach 15 to 20 centimeters in height. Artificial setae: The development of adhesives that detach at will yet display substantial stickiness is of great importance for various technological fields" Source and further information: http://en.wikipedia.org/wiki/Seta 2) "The toes of the gecko have attracted a lot of attention, as they adhere to a wide variety of surfaces, without the use of liquids or surface tension. Recent studies of the spatula tipped setae on gecko footpads demonstrate that the attractive forces that hold geckos to surfaces are van der Waals interactions between the finely divided setae and the surfaces themselves. Every square millimeter of a gecko's footpad contains about 14,000 hair-like setae. Each seta has a diameter of 5 micrometers. Human hair varies from 18 to 180 micrometers, so a human hair could hold between 3 to 36 setae. Each seta is in turn tipped with between 100 and 1,000 spatulae. Each spatula is 0.2 micrometres long (200 billionths of a metre), or just below the wavelength of visible light. These van der Waals interactions involve no fluids; in theory, a boot made of synthetic setae would adhere as easily to the surface of the International Space Station as it would to a living room wall, although adhesion varies with humidity and is dramatically reduced under water, suggesting a contribution from capillarity. The setae on the feet of geckos are also self cleaning and will usually remove any clogging dirt within a few steps. Teflon, which has very low van der Waals forces[citation needed], is the only known surface to which a gecko cannot stick. Geckos' toes seem to be "double jointed", but this is a misnomer. Their toes actually bend in the opposite direction from our fingers and toes. This allows them to overcome the van der Waals force by peeling their toes off surfaces from the tips inward. In essence, this peeling action alters the angle of incidence between millions of individual setae and the surface, reducing the van der Waals force. Geckos' toes operate well below their full attractive capabilities for most of the time. This is because there is a great margin for error depending upon the roughness of the surface, and therefore the number of setae in contact with that surface. If a typical mature 70 g (2.5 oz) gecko had every one of its setae in contact with a surface, it would be capable of holding aloft a weight of 133 kg (290 lb): each spatula can exert an adhesive force of 10 nanonewtons (0.0010 mgf). Each seta can resist 10 milligrams-force (98 µN), which is equivalent to 10 atmospheres of pull. This means a gecko can support about eight times its weight hanging from just one toe on smooth glass." Source and further information: http://en.wikipedia.org/wiki/Gecko