If any kid stops by and asks to help...pending the situation..I may allow some help but will allows give the opportunity for idle conversation. As for a kid sitting and watching...well just watching someone and their actions is a GREAT learning tool. A kid sitting and watching adult do their tasks is FAR better than him/her having their nose stuck in a video game. Most adults do know more about things and how they work...so a kid watching is always welcome to me....heck I watched as a kid and am still amazed at how many things I learned.
Anyone remember Beaver Cleaver? How much did he sit and watch adults?