This is interesting question with at least couple options. So, let's dig in…
On Thursday, 20th of November, Peter Eisentraut committed his own patch, which adds new command to PostgreSQL: TABLE.
While this command doesn't do anything that wasn't available earlier, it's worth mentioning, as it's one of patches that make PostgreSQL compatible with SQL:2008.
Basically new command “TABLE" acts like an alias to ‘SELECT * FROM':
On 28th of October Tom Lane committed his patch that changes some internals of functions, but it also adds interesting capability.