I think it largely depends on how much it costs you to provide a customer account. If this cost is low, I agree with others that #1 is the best option.
See, I tried option #1, and my product, well, it costs me quite a lot. I found that very few of my first month free trials converted to paying customers, they all used bandwidth like crazy, and looking, I believe that the majority of signups used fake names. At the end of this trial period I was left with a rather hefty bandwidth bill and a whole lot of now empty servers. it was pretty miserable. I don't think my actual paying customer signup rate was any different than it was the month before.
so for my business, #2 is the only way to go.
On the other hand, if the cost to you of hosting these free customers is almost nothing, and you are okay with the fact that your conversion rate will probably not be as great as you think it will be and that many of your customers will likely sign up with fake names just to try it out, option #1 might be just fine for you.