Portable External Hard disk

[xplorer]

Hi,

I did some searching on portable external hard disk but could
not get a satisfactory answers. Wonder if some one is familar with it.

My questions:

1) Does it require external power ?
Can USB interafce provide sufficient power ?
(some yes and some no - The only thing that I am prettty sure if that
3.5" desktop type of drive definitely requires external power source.

2) Is it hot-swappable (IOmega claims and some others - yes)

3) Is it bootable ?

Some suppliers include storix, Buslink, IOmega etc.

thanks
Adrian