I think that we should try to collect all usefull papers/information/codes on shadowmapping there is on the internet.
We should make a difference between approaches on softshadows and ways to get rid of aliasing.

I start with techniques for less aliasing -> higher Shadowresolution near to the player, less "flickering", ...:

• Yesterday I succeeded with implementing the technique presented in this great article: http://www.softgames.de/developia/viewarticle.php?cid=27884 (German)
  Schrompf also presented it here: http://www.gamedev.net/community/forums/topic.asp?topic_id=405955&PageSize=25&WhichPage=2 (English)
  
  
• LiSPSM: http://www.cg.tuwien.ac.at/research/vr/lispsm/ it is explained a bit easier with examplecode here: http://www.cg.tuwien.ac.at/~scherzer/lssm/index.html
  
  
• PSM: http://www-sop.inria.fr/reves/publications/data/2002/SD02/PerspectiveShadowMaps.pdf
  
  
• TSM: http://www.comp.nus.edu.sg/~tants/tsm/TSM_recipe.html
  
  
• Parallel-Split Shadow Maps (I am not sure but I think my implementation with 3 cams with different arc-values seems to be a bit similar): http://appsrv.cse.cuhk.edu.hk/~fzhang/pssm_vrcia/
  

And these are about softshadows:

• Variance Shadowmapping: This is the original paper http://www.punkuser.net/vsm/ (I got the example code working but it is much to complex to understand the idea)
  and this is a great NVIDIA paper which is very easy to implement: http://developer.download.nvidia.com/whitepapers/2007/SDK10/VarianceShadowMapping.pdf
  
  
• "Screenspace Blurring": http://www.gamedev.net/reference/articles/article2193.asp
  
  
• Softshadows with Smoothies: http://people.csail.mit.edu/ericchan/papers/smoothie/
  
  
• PCSS: http://developer.download.nvidia.com/shaderlibrary/docs/shadow_PCSS.pdf
  

I am sure that there are quite some good ressources missing, so please add all you know of
And then when it seems that we have most of them together I´d like to discuss them a little bit to exchange some experiences and hopefully end with some nice implementations (or at least one great )