As a DM, its easy to give NPCs long swords, bastard swords, and more, as the previous page described by Will, people in the medieval ages were creative and your games can be too.
With that in mind, here are some ideas for stats of the items described on the previous page.
Lantern Shield - I'd recommend treating it as a light shield (+1 AC) but with an additional -1 to the armor check penalty for a total of -2, treated as having shield spikes as described in the PHB (or the d20srd here) and the ability to hold a standard lantern. Additionally if the lantern is closed the user can open the shutter to dazzle an opponent, getting a +5 to bluff checks to feint in combat (SRD description for feinting in combat here)
Triple Dagger - The triple dagger should probably function similar to a sai in the sense that it has a +2 to disarm checks, but also retains the the same +2 bonus on Sleight of Hand checks that normal daggers do for concealment since the extra blades can be collapsed. 1d4 19-20/x2 Piercing or Slashing. Its up to the DM whether it should have a range increment or not, my guess is that it wouldn't be weighted as well for throwing.
Mancatchers are listed in 3rd edition, the Arms and Equipment guide I believe, if anyone knows of a 3.5 book that lists the stats maybe post a comment in the forums?
In AD&D, Caltrops were listed as a weapon I believe, but in D&D they are listed in the PHB, or here in the SRD. Personally, as a DM, I rarely use these things, but it seems often I have a main villain who I want to get away and sometimes doesn't, it seems I should probably be using caltrops in these situations.
As an additional DMing note, special equipment can help differentiate opponents in a way that descriptions often won't. It can be quite tiring to try and come up with descriptive ways to uniquely describe the 23rd orc, but merely switching out the standard weapons for something more interesting can dramatically help to make the opponents memorable. Perhaps facing a group of rogues with triple daggers ends up with the players disarmed, or the paladin could be dismounted by a mancatcher, the battles definitely become more memorable and "shouldn't" be that much more difficult to run. An interesting side effect of arming NPCs with unique weapons is that its possible the players will become more distinctive themselves, preferring to use picked up magical unique weapons than more straight forward fare (though care should be taken not to punish players who have specialized in a certain type of weapon).
The previous page's article was done by Will Kalif, the author of two Epic Fantasy novels and a big fan of all things medieval. If you would like to learn more about Medieval Weapons, Armor, and Castles visit his website at Medieval - The Medieval Armory. The above addendum was done by Richard Mathis, writer of Dndorks.com