If you mean to store some money on a card for later use, your best bet is to get either a secured credit card or a prepaid debit card.
Prepaid cards generally have a fee to purchase the card itself (anywhere from $3 to $10 usually) and won't have any effect on your credit, but you don't have to worry about spending more money than you have. You can also add more money at any time. Watch out for dormancy fees though; if you're planning on just storing the money without needing ready access to it you're better off getting a savings account or a CD, both of which will earn you interest.
Secured credit cards can help you build credit if you don't have any or help you improve it if yours is bad, and some may be found without fees, but you do have to pay back any credit you use (with interest if you don't pay it off each month) and might be able to "go over" your limit which will incur additional fees. When you close the account though, you generally get your deposit (the amount of money "stored" with the card to open the account) back, and sometimes with interest.
I don't know of any specific website I could recommend, so I would suggest doing a web search; be careful though and thoroughly read through all the terms and conditions of the offer BEFORE submitting an application as there are some cards that will cost you more than they're worth if you make the slightest mistake with it, and there are some that are outright scams and might steal your money or your identity. I would also check the card issuer - both the company name for the card AND the issuing bank (look in the terms and conditions to find this) with the BBB (http://bbb.org/us, click on "check out a business or charity) before signing up.
If you're looking for a free card that will let you take out money like a cash advance, I'll be honest - unless you have perfect or near perfect credit there are hardly any fee-free cards anymore due to all the Federal regulation changes regarding credit and debit cards. Almost all have an annual fee now, and some even have a "dormancy" fee if you don't use it at least every so often.
I hope this answers your question!