Intervalometer (time-lapse cable) for GH1-2-3?

Hi can anyone tell me of a good reliable intervalometer or similar device I can use for time-lapse photography with GH1 (but also hopefully to be compatible with GH2 and future GH3)?

I remember that the only one that used to be available was called JJC or something like that, but a lot of people complained that they broke easily and didn't work well.
Is there something better out these days?

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