Mssql 2005 Problem, To Many Requests, Need To Optimize

Hello, I have a bit of a problem. Some of my pages has way to many database requests, some pages upto 70 requests,
and the loading time can be all the way up to 12seconds because of the many requests. So i am trying to optimize it abit.
What i want to know if how to send several ID's to the database and collect the result from all of the ID's, i have a stored procedure like this:



public DataTable User_GetUsernameTypeTwo(string strUsername)
{
OpenDBCon();
mCom.Parameters.Clear();
mCom.CommandText = "Profile_GetUsernameTypeTwo";
mCom.Parameters.Add(new SqlParameter("@UserName", SqlDbType.NVarChar, 20));
mCom.Parameters["@UserName"].Value = strUsername;
myAdap = new SqlDataAdapter();
myTable = new DataTable();
myAdap.SelectCommand = mCom;
myAdap.Fill(myTable);
CloseDBCon();
return myTable;
}

To this i send a username and in return i get info about the user that then is presented on the page. If i have a gridview on the page with 20 posts, then it needs to make 20 requests to this file in order to collect all the info for all the users. Then i have one just like the one above that collects the photos of all the users. So my first thought was that i merge these two together, witch works perfect, reduces the database calls by around 40%. Then i thought, perhaps can i get all the info from all the users in 1 request, to reduce the load on the database even more, my problem is: How can i rewrite the one above to accept lets say 50 usernames (1 username can max have 20characters), and return the info from all of them. Since i use a stored procedure i cant with ease use WHILE (username = xxx) AND (username = yyy) AND (username = ccc), then i would have to add 50 Parameters and add each username to a seperate parameter and then look if the parameter is null or if it contains a username. So i need to find another way to send the usernames, so the sqlserver can add them to the where clause, perhpas using IN?

This is the sql server store procedure (it works perfect, when its one user i am requesting info about), i am using FULL OUTER JOIN because ALL fields i request can be NULL:

ALTER PROCEDURE [dbo].[Profile_GetUserpopupInfo]
-- Add the parameters for the stored procedure here
@UserName nvarchar(20)

AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
SELECT settings_username.color, settings_username.pic1, settings_username.pic2, profile_profilephoto.imageurl, profile_profilephoto.alttext FROM settings_username FULL OUTER JOIN profile_profilephoto ON profile_profilephoto.username = settings_username.username AND (profile_profilephoto.approved = 1) WHERE (settings_username.username = @UserName)
END

Anyone got any idea of how to send a bunch of usernames to this stored proc? (it must be efficient since there is alot of users)

Patrick