pizzapop: Two freestanding supports, even in an L shape, generally would not be able to support the load, even for one person, and would pull in together, and overturn.
Instead, perhaps try something like this
hammock stand[/color], shown also
here[/color] or
here[/color], taken from, e.g., http://hammocks.com/hammock-stands/metal-stands/exclusivedeluxefauxwoodhammockstands.cfm page. Or http://ak1.ostkcdn.com/images/products/3/L11162998.jpg it is again, from, e.g.,
this[/color] page.
They claim it can support a maximum occupant weight of 2000 N. The round steel tube size (outside diameter and wall thickness), of the larger tubes, appears to be perhaps 42.9 x 2.11 mm (?). But someone would need to actually measure and confirm the outside diameter (OD) and wall thickness of the above tube. (I am currently not sure if the OD of the larger tube shown in the above images is 41.3, 42.9, 44.5, or 47.6 mm.)
You could alternately use this
double[/color] tube style.
Here[/color],
here[/color], and http://img844.imageshack.us/img844/7936/dwrmx.jpg is another approach, which works well, using galvanized steel pipe supposedly having an OD of 33.4 mm, and a wall thickness of 3.38 mm. In the particular case of the second and third images here, this particular person used dimensions A = 3050 mm, B = 1525 mm, C = 915 mm. (However, his dimension C value sounds too small, and should be increased, to achieve adequate stability. Notice in the fourth link in paragraph 2, above, for a hammock attachment height of B = 1140 mm, they use dimension C = 1220 mm.) Also, most sources seem to recommend A = 3650 mm to 4570 mm, instead of 3050 mm. However, for dimension A > 4000 mm (?), you might need to increase the top horizontal pipe size to an OD of 42.2 mm, and a wall thickness of 3.56 mm. If you give us the exact dimensions you want to use, and the exact pipe or tube outside diameter and wall thicknesses available, which you plan to buy, then we might be able to get a better idea of adequacy.