I've migrated completely off my computer to my smart phone and cold storage. Mycelium works great for storing coin and also spending from paper wallets.
Is mycelium new or something didn't heard of it, basically i want to buy Bitcoin send to my wallet and send o an exchange, but first want to send it to my wallet so need something simple like the original, do you know how much space the bitcoin-qt takes?
Bitcoin QT takes up a ton of space, which is 17 GB right now.
I suggest >Electrum.
Dude says he wants to use a phone.
Electrum was a p.i.t.a. to install on my android device.
I use an android tablet (Nexus 7), which doesn't come with
java python. Installing Electrum was a very involved process, and I didn't even succeed on my own. A computer expert friend of mine had to do it for me.
If you have a device that has
java python, it would be much easier.
To import a private key or spend from cold storage, mycelium is the best. Bring up a qr code of the private key and point the phone at it. I don't think you can do that with other wallets.
I boot my laptop from a live linux usb, open bitaddress.org offline, and type in my brainwallet passphrase. That brings up the qr codes for the address and key. Then I get my tablet with mycelium on it and point it at the qr code for the private key. In mycelium you can import the key, which gives you access to the entire contents of the brainwallet/cold storage, or you can do a partial spend from it.
You sacrifice some privacy with partial spends, and you also sacrifice some security because the spend exposes your public key, which has less entropy than the address does; it also exposes prng vulnerabilities which don't exist otherwise.
NOTE: Mycelium does not have its own child board under "Alternative Clients," but it does have a very active thread on that board which is now about 35 pages long, with lots of good information.You should go there and have a look.