Visit this page to view a list of the Locale IDs (LCID) applied in XSL format statements to select the appropriate one for your particular needs if date, time, currency, or all of the above are not displaying in the desired or needed format on a Data View Web Part. (This also applies to Content Query Web Parts.).
 
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.