LiteSteel Beam

Ok here's one I've used before but slipped my mind until I saw a post on a US site... couldn't find any sustainable info on the site which is generally not a good sign, however this product has some great credentials in terms of ease and speed of working, good range of standardised components, and minimised weight/material + developed in Australia and I'm pretty sure its locally produced (need to check this). The weight advantage becomes really important when considering structural members for touring exhibits. I've used it for a raised public platform/ramped area and though still heavy, it was easily managable, constructed, happily signed off by the engineers and had the durability to stand up to touring... worth further investigation.
From the site....

LiteSteel beam was developed in response to demand for a light structural beam with the strength of steel and the ease of use afforded by timber. Its approx 40% lighter than the equivalent rated hot rolled beam. LSB delivers the same load-carrying capacity as hot-rolled steel, and it can be worked like engineered wood (cuts, nails, and can be integrated with wood framing with standard connectors)LiteSteel Beam