small projects to network with other programmers
RobGR: Real world meetups for joint hacking are better than online collaboration.  If the goal is to learn from other programmers, you learn a lot more by sitting next to them.  A lot of it is incidental stuff you would not have thought to ask, like tricks in vi and emacs and etc.  Another reason to work with someone is it provides a kind of social discipline, you feel you have to get something done on the project on a semi-regular basis.  A weekly hacking session at a coffeehouse or someones apartment provides that regular discipline, and because the hacking sessions inevitably end, physical meetings can keep a side project from growing and taking over the rest of your life.The "just work on a open-source project" advice isn't that bad, but you should pick something that you would benefit from improving.  It is still a good idea to solict others to help you in a physical meeting, however.  Find people who would benefit from improvement in the same project.I think rather than a website or webapp, what you are looking for is a computer club.  I go to a weekly meeting in Austin of ALE, a linux users group.  We meet 7 pm to 11:30 pm, and we are an "experimental" group, in that we never have presentations or a planned agenda -- people bring computers with problems and we fix them, new people show up asking for help learning linux, etc.  There are about 5 people there who come regularly with programming issues, ranging from side-business startup sites that are in php and mysql to hobbiest robots.If you are really serious about this, find a place (possibly your house or apartment) and have a "Saturday afternoon hack-a-thon" every week or every other week.  If you provide food and coffee people will come.  Your main problem is likely to be keeping non-programmers from showing up and just talking.If you have trouble finding a place to do this, see if you can locate a co-working or "jelly" type place in your area.     A co-working place might let you use the area during non-business hour such as on weekends, and the jelly people probably know all the good coffeehouses.