There are several yahoo groups that are Shetland related. Here are a couple that I belong to:
ClassicShetlands, Arenosaponiesforever, Shetlands-for-Sale. Classic Shetlands is quite active. I believe there is also a Modern group? There are also some less active groups; Shetlandtalk, Shetlandchat, Shetlandissues. I also belong to some non-breed specific groups that welcome Shetland people; PacificNorthwestPonies, Driving Horses, Pony-L, PonyClassified. I think I got those right. If you join yahoo groups and search Shetlands or Ponies, you should find more than enough to keep you busy and drooling for the next few years, LOL. You do have to choose 'mail' to see pictures on yahoo.
There are a couple of sale boards, for both shetlands and arenosas, on voy. I don't have the links at hand, but you can get them on the above groups. My most recent pony purchase was found on the LB sales board though. :bgrin Also watch the ASPC/AMHR Journal for upcoming sales and auctions. There are some VERY nice ponies to be found at some of these.