Is it 100% safe? Of course not. But general consensus is that it's not a big risk. Most stories just go like this "I spent my money and I didn't get my seeds. I did get a letter from Homeland Security, bummer." There is, of course a thread devoted to the discussion here:http://boards.cannabis.com/legal/125...-internet.html
Yes, many of us in the states have ordered seeds.

The level of discretion varies greatly depending on who you place your order with. Generally seeds are shipped in DVD cases or CD cases or some such thing, though not always. A few seeds banks will ship to you in a T-shirt or other such item for an additional charge. Check this thread for help deciding who the guys and the bad guys are: http://boards.cannabis.com/basic-gro...-good-bad.html

Also, more specific thread titles will generally get you more responses, and keep in mind that many, many other of these basic questions have been addressed innumerable times and answers can easily be found by using the search function.

Good luck.