Upvote:4
Belgium is one of the more expensive countries in Europe when it comes to mobile internet. The cheapest provider I have found so far is the Aldi, but they don't ship, you actually need to buy it at the aldi stores.
Similar formula's are offered by Delhaize and carrefour, but their online descriptions are not really clear about mobile internet. Both are also supermarket chains, but compared to the Aldi they have longer opening hours (till 20.00).
You might have better luck with wifi. Fon has great coverage in Beligium. I can maintain a good coverage with expensive 3G and "free" wifi access through FON.