Examples of usage:

<xp:TextBlock Text="{Binding Path=[budget.description], Converter={StaticResource TrimTextConverter}, ConverterParameter=100: :... (read more)}" Padding="4,1,0,0" />

<TextBlock Foreground="Black" Height="Auto" TextWrapping="Wrap"  HorizontalAlignment="Left" Text="{Binding Path=[article.plainText], Converter={StaticResource TrimTextConverter}, ConverterParameter=200: :...}" FontStyle="Italic" />