Does somebody know exist a control for a visualwebpart that allows to select an user/control?
I am creating a form using a visual web part and i want to allow to select an user.
I am searching for this control:

thanks.
It's the PeopleEditor control. Here's the good article about it. It's about 2007 version but there's no changes in 2010.
To add the normal people picker to a web part you can use
Microsoft.SharePoint.UserControls.PeopleEditor or
<SharePoint:PeopleEditor ID="myPeoplePicker" runat="server" Width="300" BorderStyle="Solid" BorderColor="Black" BorderWidth="1" />
Check out the below link, it has complete code:
http://salaudeen.blogspot.in/2012/04/using-people-picker-in-web-parts.html
http://sharepointbyte.com/how-to-call-a-people-picker-in-visual-web-part-in-sharepoint-4/
Check out the above link, it has complete code: