I have only 512 Mb flash drive. Is it possible to create bootable Maverick 10.10 on it? Maybe, with some packages dropped? What tool can I try for it?
You could try using Ubuntu Customization Kit available here http://uck.sourceforge.net it let you create a custom distribution based on Ubuntu with packages you need. You should also be able to customize language pack, default language, keyboard layout ecc... I hope it helps.
There are many light weight distributions such as Lubuntu, Xubuntu, EasyPeasy (soon with 10.10 based version 1.7.), Puppy (still based on Lucid) - to name just a few - that have already done the job. If you need additional packages or another desktop you can alway install this later until your flash drive is full.