The steps below allow you to add a "Welcome to the site, Jane Doe!" welcome message to a page. We did this to insert it to an Announcement list.
1. Using SharePoint Designer, insert a Data View Web Part based on the Announcement list;
2. Select Data > Conditional Formatting;
3. Select any data value and select Create;
4. Select Show Content;
5. Create a condition that reads Title EQUALS [Current User] and select [OK];
6. Go back to the Design view;
7. Type "Welcome to the site, " inside one of the Table cells;
8. Switch to Code view;
9. Find the following code:
<ParameterBinding Name="UserID" Location="CAMLVariable" DefaultValue="CurrentUserName"/>
10. Change this code to:
<ParameterBinding Name="UserID" Location="CAMLVariable;ServerVariable(LOGON_USER)" DefaultValue="CurrentUserName"/>
11. Scroll up in the code and find "Welcome to the site, "
12. Change this code to: "Welcome to the site, <xsl:value-of select="$UserID"/>"
13. Save the page.