Attached patch adds an optional format argument to time.time():
time.time("float") is the same than time.time(), but
time.time("decimal") returns a Decimal object. The Decimal object
stores the resolution of the clock and doesn't loose lower bits for
big numbers. I configured the Decimal context to be able to store
10,000 years in seconds with a resolution of 1 nanosecond and
ROUND_HALF_EVEN rounding method.

Example: time.time("decimal") returns Decimal('1327495951.346024').

It is really cool for have directly the resolution in the result,
because the resolution may change at each call: time.time() has 3
different implementations (with fallbacks), each has a different
resolution. time.clock() has also 2 implementations (one is used as a
fallback) with different resolution.

The internal time_to_format() takes integer arguments: the floating
part is written as (floatpart, divisor).

If you like the idea, I will also write a patch for time.clock(),
time.wallclock() and time.clock_gettime(), and also maybe for
time.clock_getres().

We may use a registry to allow to add user defined formats, but I
prefer to keep the patch simple (only allow "float" and "decimal"
right now).