Can we concat two properties in data binding?

If you want to show, say FirstName and LastName, in a single TextBlock, then you can do like this:

<TextBlock>
     <Run Text="{Binding FirstName}" />
     <Run Text="   " /> <!-- space -->
     <Run Text="{Binding LastName}" />
</TextBlock>

Now, the TextBlock's Text property will be "Sachin Tendulkar" and will be displayed if:

FirstName = Sachin
LastName  = Tendulkar

Hope that helps.

<TextBlock.Text>
   <MultiBinding StringFormat="{}{0} , {1}">
     <Binding Path="data1" />
     <Binding Path="data2" />
    </MultiBinding>
</TextBlock.Text>

data1 and data2 are string properties which are binded.

Like alpha-mouse suggests MultiBinding won't work out of the box, but this guy has thrown something together that might help:

http://www.olsonsoft.com/blogs/stefanolson/post/Improvements-to-Silverlight-Multi-binding-support.aspx

If that seems a bit rogue, then maybe try putting a combined value property on your object as a helper for the Binding mechanism, like:

public string FullName {
   get { return this.FirstName + " " + this.LastName; }
}

It is possible in WPF with the help of MultiBinding and StringFormat. But not in Silverlight unfortunately.