Lakeshore Learning Store in KOP has free Saturday craft classes for kids age 3 and up. If you go to Lakeshore's website, it gives you the dates, times, and craft for that week. I have friends whose kids are not yet 3 and they still participated, so if your son is almost 3, I'm sure it would be fine. As far as classes, don't know of any other free ones. However, there are lots of free places to take him around here.......Linvilla Orchards in Delaware County, Merrymead Farms in Worcester/Lansdale area, summer concerts at local parks, etc. Also, try a google search for Activities for Kids in Philadelphia area. I did that and it came up with a lot of ideas.