Programming/Coding Problems and Challenges Websites.

Top Coder : http://topCoder.com
Code Chef : http://www.codechef.com/
ShareCode : http://sharecode.ir/
Interview Street Challenges :https://www.interviewstreet.com/challenges/
Code Golf : http://codegolf.com/
Leet Code : http://leetcode.com
Project Eureka : http://projecteureka.org/problem?category=Programming
Project Euler : http://projecteuler.net/
Sphere Online judge : http://www.spoj.com/problems/classical/
Code Eval : https://www.codeeval.com/
Reddit programming challenges: http://www.reddit.com/r/programmingchallenges
UVA Online judge http://uva.onlinejudge.org/
Google Code Jam http://code.google.com/codejam/
http://train.usaco.org/usacogate
https://sites.google.com/site/prologsite/prolog-problems
http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml
http://acm.timus.ru/
http://www.olympiad.org.uk/
http://domino.research.ibm.com/comm/wwwr_ponder.nsf/pages/index.html
Rosetta Code: http://rosettacode.org/wiki/Rosetta_Code
http://poj.org/problemlist
http://www.rankk.org/
http://codekata.pragprog.com/2007/01/code_kata_backg.html#more
Facebook Programming Challenges: http://www.facebook.com/careers/puzzles.php