Engadget posted on a device that may be able to answer both problems. The WL-16III walkbot, a joint project between Waseda University and tmsuk, is a chair with two legs. The 'driver' guides the walkbot with a pair of joysticks.
While the researchers envisioned the Walkbot for elderly or physically-challenged individuals, it's a safe bet that able, but tired, folks will be more that willing to rent them at auto shows or concerts.
[Source: Reuters via Yahoo! News via Engadget]