Any plugin that has a portable light source?

Well, Me and my friend thought it would be nice to have a object (torch, glowstone, etc) in the inventory/hotbar and make the player who has the object glow... for easier mining purposes.

 

If you want to have the effect of "holding a torch" you will need a client mod. There are, however, plugins that can make a lamp block or similar "follow" the player, but it doesn't sound like what you are looking for.
A way I could imagine to do this by a server plugin is to check if item X is on the hotbar and if yes apply a Potion of Night Vision to the player.

 

That would be nice and all, but would it be POSSIBLE to allow the server to change the light levels in proximity to the player while the player has a specific item in the inventory?

 

Cheesington
No. Lighting us handled client side. What you can do however is make an imaginary glowstone block/torch follow the player. Only the player can see the lighting/block which is really nice.

 

Yeah... I've tried something similar to that before... the client thinks it's bright and fancy... but the server sees a dark cave... So, since the server sees a DARK cave, and monsters spawn in DARK areas, the server starts spawning monsters, Which will surprise the player.

 

Lightning is handled by the server and by the client, so it is possible.