I'll be the first to admit I'm not by far the foremost expert on Leuven having only visited a couple times myself, but I thought the following information may be useful for anyone wanting to visit such a beautiful city.

Weather:
Even during the June-July months, Leuven's weather alters quite signficantly during the day and the evening. A change of clothes is suggested since the nights may be a bit chilly on occasions. A light cardigan or windbreaker might be of use.

Summer showers: Your visit may also be frequented by short sudden showers so a travel umbrella may not be a bad idea either. For temperature information, visit weather.com and search for Brussels, Belgium. (please note that showers will not likely be included in the forecast since they are often sudden and short).
ATMs/Cash:
If you find that you're short on cash, you'll be happy to note that there is a Citibank and a Barclay right in the middle of town on Bondgenotenlaan. For Citibank customers, there is no transaction fee if you hold an account with Citibank in the States. (Even if you don't have an account, the transaction fee still might beat the surcharges for currency exchanges). For detailed info check out citibank.com. For up-to-date currency exchange info, visit FXConverter to find out how much the dollar (USD) exchanges for the euro (EUR).
 
Languages:
Belgium is a trilingual country, speaking Dutch (or Flemish), French, and German (and exactly in that order in Leuven - wink). Of course most people also speak English. So relax, you'll be able to get around if you ask for directions but don't plan on being able to read.
 
Restrooms:
Unless you are at a restaurant, many places may require a small fee for usage of their facilities. These places include tourists spots, shopping centers, and train stations. Be sure to have 20-30 cents on you if you're the bladder-challenged type like myself.
 
Dining and Tipping:
For restaurants and dining facilities, tipping is already included on your bill, but... you do have to ask for the check since it is considered rude for your servers to interrupt your meal or conversation with it. Also be sure to allot enough time for a meal if you are eating in a restaurant between events. Some places may go from 2-3 hours if you decide to order a full four course meal.
 
Pharmacies and Over-the-counter drugs:
All over-over-the-counter medicine must be purchased at a pharmacy/apothecary. They are noted with a green cross hanging above the store entrance. You will not be able to locate them at the local convenience store or at the supermarket. Common medicine such as Benadryl and Tylenol have different names. (e.g. Tylenol --> Panadol).
 
Must Tries:
Besides the chocolate and beer, you must try the Belgian waffles. My suggestion is at Timory's on Brusselsestraat.
 
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