I have been playing for about 4 months and I'm not sure where to go now to get better. I have all the open chords down (well, the common ones at least), I am ok at all the barre shapes, good at power chords. I have done some work with arpeggios and sweep picking etc. Any advice from someone who remembers this time in there guitar history? Thanks.
1. learn theory, it'll improve your playing by miles, you'll be able to visualise what you're playing and it'll help your improvisation abilities
2. keep training arpeggios and sweeps if you're into that kind of music (metal and variants), I myself am not really into that, so I haven't learned it (yet).
3. Definitely use a metronome to get even faster
4. Just keep playing!
Fender Jazzmaster
Boss DS-2
Digitech RP150 (with Line6 EX-1 Exp pedal)
Orange Crush 30R

My Youtube Page
Read this!You know you really want to...

Have a look at some scales or try learning some songs or a solo all the way through. You could try fingerpicking, tremolo picking, etc. Learn some music theory, and develop your sight reading. There's lots more you can do.
Find a song that makes you think "woah, there's no way I can play that" and spend time learning it.
You could learn palm mutes, hammer ons and pull offs, tapping, pinch harmonics, harmonics, theory, alternate picking, slides, trill (hammer ons and pull offs fast ish) and what everyone else has suggested
They made me do push ups in drag

I'm gonna have a really hard time if we're both cannibals and racists.

Don't dress as a whore, he'll thump you.

I'm a firework, primed to go off