If you want your house to look a little more like a set piece for Arachnophobia, this Electronic Webcaster Gun should do just the trick. It's loaded up with "Web Sticks" that give it something of a glue gun feel, but — instead of hot glue — it shoots out icky streams of webbing.
You've got a few options, here:
One package of Web Sticks covers approx. 350 square feet, or one 12-ft. x 15-ft. room. Choose Clear for traditional webs which glow blue under black light; Glow In The Dark for an even stronger eerie effect; or Neon Yellow for webs that glow yellow under black light.So, unless you're Spider-Man, it's probably the easiest way to get those webs in hard to reach places. The Webcaster itself along with six sticks costs $50, while replacement sticks are bought in packages of 20 for $6.
Update: As Realist pointed out in the comments below, you'll need an air compressor rated for 90 psi.