Update January 2010: Poisonous yellow lichen Letharia vulpina mixed with ground glass or fat in reindeer carcass used to poison wolves. http://en.wikipedia.org/wiki/Letharia_vulpina
The use of this species for poisoning wolves and foxes goes back at least hundreds of years, based on the mention of the practice in Christoph Gedner's "Of the use of curiosity", collected in Benjamin Stillingfleet, Miscellaneous Tracts Relating to Natural History, Husbandry and Physics (London, 1759). According to British lichenologist Annie Lorrain Smith, reindeer carcasses were stuffed with lichen and powdered glass (small chert flakes?), and suggests that the sharp edges of the glass would make the animals' internal organs more susceptible to the effects of the lichen poison. However, it is known that the lichen itself is also effective—powdered lichen added to fat and inserted into reindeer carcasses will also be fatal to wolves that consume it. The toxic chemical is the yellow dye vulpinic acid, which is poisonous to all meat-eaters, but not to mice and rabbits. (hat tip to Brian & comments at Laelaps).)
After more thought on hand axes, I now think that by 1ma they were primarily used as simple tomahawks and later adzes, using hand-wound roots/vines to attach the bifaces to wood handles.
However, it is not unlikely that small biface stones, chert/obsidian flakes, razor clam shards or sharp sticks could have been inserted into fish or game meat/fat/organs as night-time bait-traps against any nocturnal predators around the cave or beaver-lodge-style hut camp.
Hand axes in Crete: Crete bifaces
Stone hand axes unearthed on the Mediterranean island of Crete indicate that an ancient Homo species — perhaps Homo erectus — had used rafts or other seagoing vessels to cross from northern Africa to Europe via at least some of the larger islands in between, says archaeologist Thomas Strasser of Providence College in Rhode Island. Several hundred double-edged cutting implements discovered at nine sites in southwestern Crete date to at least 130,000 years ago and probably much earlier, Strasser reported January 7 at the annual meeting of the American Institute of Archaeology. Many of these finds closely resemble hand axes fashioned in Africa about 800,000 years ago by H. erectus, he says. It was around that time that H. erectus spread from Africa to parts of Asia and Europe.
Original from 2007:
I've read that one way Inuits reduced competition from wolves was by inserting a sharp blade into a chunk of meat, swallowed it would tear up the stomach and kill it.
Could a hand axe or sharp blade be put in a fish or meat bait at waterside to kill a lion, sabercat, leopard, tiger, crocodile? (Rhetorical question)
Since unlike hyenas they don't crack and eat the bones, they may be susceptible to something sharp lodging in the GI tract.
Crocs (and seals and other aquatic animals) swallow rounded stones for ballast. Louis Leakey found near-sphere pebbles ("bolas") among masses of hand axes in the Rift valley at Olorgesailie, according to Rick Potts. Thanks to Lee Olsen for bringing Potts article to my attention.
Fishermen fishing for catfish in some areas attach chicken or other meat materials wrapped around a stick sharpened at both ends, which lodges in the pharyngeal-GI tract.
East of the Movius line in Asia, bifacial hand axes are only rarely found (Unlike Africa, Europe and west Asia). Most likely bamboo slivers were used instead.
Tyranosaurus Rex didn't chew, it tore flesh into chunks, probably tossing them into the air and swallowing whole, similar to how Orcas toss baby seals and cats toss mice. Crocs and big cats have their own methods, but have some resemblance to this style of carnivory.
I don't think hand-axes aka bifacials were simply the result of knapping flakes, nor do I think they were used effectively as frisbees. (As I said in Paleoanthro.) I think the butted hand-axes
were used in woodcraft and possibly bone splitting, the cleavers were used in butchery, the "beautiful" ones perhaps as social trade/status items, but the majority which according to Mikey Brass were found at waterside, were used as bait traps for carnivores that did not habitually chew medium-sized chunks of meat or fish but rather swallowed them whole without chewing.
If effective in terminating competition, it would not be surprising that hand-axes continued to be in use for such a long time with little modification. The unique flattened teardrop shape being effective for swallowing but not regurgitating.
I'd appreciate any relevant comments.