I wasn't in any hurry to make one for my kids because they were still quite young. Then some time last year I saw a post on the "Crafty Crow", showing how "Mamma Jenn" had made one using cork board pins. My kids would be trying to pull the pins out even if I glued them in, so I wasn't sure about trying that.
Around this time my friend Jennifer found a large bit of board in the garbage room of her apartment block and brought it over for me, knowing that I like to make stuff out of other people's trash (thank you Jennifer!). This is the sort of board with holes drilled in, that you mount on the wall to put fixtures in to hang tools etc. I thought it would be perfect for a geoboard if we used some nuts and bolts to make the pegs.
We got a nice big box of 100 bolts and nuts and screwed them all in. The kids then got a rubber band ball each to take apart and use on the board.
We haven't done any specific learning excersizes with it yet. The kids are just exploring and playing with it making shapes. Interestingly they decided to use it to make mazes for their little toys.
Of course if you have the imagination of a three year old, all you need is a single rubber band.
At some point in the future the board will become more useful to teach geometry concepts, especially as we can remove the pegs and put them back in using different formations, but right now it's just cool that they are into imagining and exploring with it and it's no longer destined for landfill. Also, it's nice that it's big enough that four kids can crowd round and play with it at once, seeing as we often have extra kids about the house.
It's also fun for mum to play with ;) Doesn't take much to amuse me.