Format a USB flash drive using gpart

[Wojciech Puchar]

>> file system" (as you said without partitions, and I'll take
>> that literally): You can use tar, "the universal file system
>> that isn't a file system" to write data to the USB stick.
>

which is best in USB pendrive wear and speed point of view.

pendrive's flash translation layers are just awful, only linear writes 
works well.

>> Writing stuff:
>
>>         # tar cf /dev/da0 /my/files

i would recomment

tar -b 128 -cf /dev/da0 /my/files

> Might
> # tar xf /dev/da0
> work in other BSDs or even other (quasi-)Unixes including Linux, using the appropriate device name where applicable in place of da0?

yes it will run fine under linux, openbsd, netbsd, slowlaris etc.

>
> While that particular construst could probably not be booted, it is possible to boot from a floppy or image file that does not contain a file system.

If you need bootable pendrive then you have to use disklabel and make 
filesystem.