There are two issues that can arise when playing a DVD from outside your own country: PAL/NTSC format, and region coding (aka RCE). These two issues are not related.
Most DVD players outside of the USA can play both PAL and NTSC. Many of them can be "hacked" to ignore the region coding.
About half of the players inside the USA can play both PAL and NTSC. Many of them can be "hacked" to ignore the region coding.
How do you "hack" a player? Usually, it involves using the remote and pressing a certain combination of buttons to access a hidden menu. Sometimes it requires you to update the firmware of the unit (you would download a file online, burn it to a CD, and then stick it in the player). A small percentage of the time, you have to buy a special remote, or have your hardware physically altered (soldering connection, adding chips, making jumps, etc).
Undoubtedly, the best archive for "hacks" online is the one located at http://www.videohelp.com/dvdhacks
Another way to get around region coding is to simply copy your disc (DVD5 with DVD Decrypter
, DVD9 with DVD Shrink). If you follow the guides on digitalFAQ.com, your new disc will have no region info at all. As long as your player can play a region-free disc (and almost all of them do!), you should be fine.
The PAL/NTSC issues can be more tricky. Your best bet, if this is a problem, is to simply buy one of those chearp $25-40 USD players from Walmart, Target or Best Buy. The Cyberhome and LiteOn brands are well-known for their ability to playback PAL, as well as their easy region code hacks (use the remote).
I always suggest people avoid trying to convert PAL to NTSC or NTSC to PAL in software, as it never turns out looking very good, and you spend countless hours trying to get it to work. It's easier to buy a second player, and if you value time (time is money!) it's cheaper too.
That should about answer it. Let me know if you need anything clarified.
Since you stated you have a DVD+R from Germany, it is most likely already region-free and your true problem is an inability to play PAL. You may want to use DVD Decrypter
to rip the disc, and then burn a new copy. Usually a DVD-R/DVD+R does not have region data on them (most software available to consumers is unable to set the region), but you never know.