Path of Exile has you covered, as the development team has just announced that the game will be throwing the doors open for a public stress test over the weekend. Whether or not you're in the closed beta, you'll be able to log in and tool around in the game to your heart's content.
The stress test will feature all of the content currently available in the closed beta. Servers will open at 8 p.m. EDT on July 27th and will close up once again at 2:59 a.m. PDT on July 30th. Anyone more interested in playing than in filing bug reports will be happy to note that the focus is just on loading up the servers and seeing how they perform under load. The official FAQ has further guidelines and a link to the client so you can get it downloaded and ready before Friday evening.