Keep in mind that most (all?) JavaScript implementations out there
will choke if you try to store or manipulate 64-bit integers (signed
or unsigned), so for all JS code, you should treat ids as strings.
Of course, since ids are pretty much opaque values, this doesn't
really cause any
I haven't been paying attention, but I haven't heard something
definitive about the id space.
Anyhow. the Negative numbers might have something to do with unsigned
long != two's complement signed long. So a 64bit id can be
represented as an unsigned long (all positive numbers), or a two's
