You know how you read a thread and get sucked in to posting......
The world according to FM:
Yep, minor pentatonic is the common clay of the guitar world. You can listen to any cheesy 3 chord rock song and hear a minor pentatonic scale.
The E-G-A chords you mentioned, as recognised as Purple Haze chords by Drew Peterson, not surprisingly is the same chords for thousands of songs; even more if you apply the same interval to a different key.
"Solos consist of licks. Well, bad solos, anyway. Good solos consist of original melodies . . ." - I couldn't agree more. If you pick to pieces all the solos in pop since day dot, you'll find it is lick based. The tricky players find unique ways to join the licks together, but really they're still playing the same notes.
Not just pop rock either. Jazz guitarists like Mike Stern and (insert many many others) have a set of licks they use as well. Take a recording from Stern from the 70's, extract the solo, plug it into one of his modern songs - It'll match note for note (with the exception of how he joins them).
Original melodies, "telling a story" or Jazz (true) improvisation are the way to not sound like everybody else.
I'm not on a high horse - I'm the same in that I too have a set Of licks that my fingers pump out when my brain turns off - but I try real hard to vary from this.
"Hell, Jimmy Page is the most overrated mofo ever. That fucker is sloppier than Ace Frehley." - hehe, couldn't agree more since we're on the bash.
Anyway, I've said to much
In an attempt to offer some advice to your original query, you can just play a minor pentatonic in E over a E-G-A progression and it will "fit". It could be a good method to get you back into the swing.
Cheers,
FM