Member+ are able to make Stargates. The 'frame' must have the 9 redstone lamps (chevrons) in the correct places, but the other blocks can be any other solid block of your choosing.
(A Stargate)
Once you have completed the frame, you must register it as a stargate by placing a sign on the center back with the text "[stargate]" on the first line. Make sure you put it on the BACK of you stargate otherwise you will have to go through it from the wrong side. You will then be prompted to activate it by using an emerald block. Make sure your gate is 100% to your liking before this step, because once you use the emerald block you will not get it back. After you activate a gate, it will update the sign and put the address on the second line. (This address is based on the actual world location. So it can not be manually set).
(Activated stargate sign on the back of a stargate)
Now that you have your gate, you need a device to dial it with. This is called the Dial Home Device, or DHD for short. You can create this by placing a sign within 16 blocks of your stargate with "[dhd]" on the first line and the stargates address on the second. You must type the address on the second line for a DHD otherwise it won't know which gate it belongs to.
(A DHD)