Went to Aglona a few weeks ago. We rode 100 km on the first day and 60 on the second. By the way, this was the first time we did close to 100 km on dirt roads. It was tough, of course, barely made it before dark. We navigated using Bing maps, which was fun — its Navteq maps are inaccurate in places, but at least they have forest roads. Because of that, as usual, we wandered around in circles. Every cloud has a silver lining, though — we got to see a small working hydroelectric power plant that we otherwise wouldn't have stumbled upon. We only found it thanks to a local resident and Google satellite imagery. (iPhone rules!)
Here are the coordinates for those who crave them: 56.04249, 26.88598
Along the way, we visited Biķernieki, Ambeļi, and Šķeltova. In the latter, there are as many as 4 shops right next to each other, but they close early on weekends, which is sad. Fortunately, there's civilization in Aglona and Saules Veikals is open until 22:00.