I believe this is the ex-pen that I got:
24" Black Pet Dog Cat Play Exercise Pen w/Carry Case - eBay (item 250350560143 end time Jan-03-09 14:35:30 PST)
I got it from ebay with free shipping, and it looks like the same one, with a door in one of the panels.
Lexi was crate trained. When I had to go out for longer periods, and then when I went back to work at the end of the summer, I didn't want to leave her in the crate for too long. I liked the idea of the ex-pen. Plus, we were doing major construction on our house. The kitchen and our bedroom were the only liveable rooms, and when they were working in the kitchen, I needed a safe place to keep Lexi.
I like the ex-pen because it gives her room to walk around. In there are her bed and some toys. When we go out, I put in her food and water, and her litter pan with the pee pad in it. I used to put her crate in it, when the ex-pen was in a corner - the crate would go in that corner. And at night, she would sleep in her crate in her ex-pen.
When we moved the ex-pen, I couldn't keep the crate in there any more because she could climb on her crate and get out of the ex-pen. Now her crate is next to the ex-pen.
Over the summer, we had to be up early as the workers would come at 7. Once the worst of the construction was over, which was when school started and I was back to work, I wanted to grab any time I could to sleep a little later on weekends. But...I didn't want to make Lexi wait too long in her crate. So eventually, I just put her in her ex-pen for bedtime, with her litter pan. That way, if she should have to go during the night, which is pretty rare, or before I get up in the morning, which doesn't happen often, she can go on her own, and we don't get awakened by her barking.
Lexi rarely uses the litter pan in her ex-pen. She prefers not to go in there, and will usually only go if we are gone for an extended time.
HTH!