If you have a browser that can load a java applet, you should be able to do this. The applet is named ZPlet and runs any of the hundreds of text adventure game files out there. Here's a game that I downloaded recently that I kind of like. It's a good intro to the medium because this particular one is pretty linear and doesn't actually allow the player to do too much - it only fakes the interactivity, which is part of the point of the plot (having to do with choices and free will). There are other games that allow you to do all sorts of things. This game is called Rameses. Click in the applet and start typing to play.
I think the applet is a bit buggy so you might want to type "restart" at the first prompt just to make sure you got everything. After that, the commands are usually 'verb noun'. You can also "talk to