I lift every day of the work week (take both weekend days off) and work out every muscle on every day. My current routine:
- mon-fri morning (10-15 minutes) : bench press, pull ups
- mon/wed/fri lunch (30-40 minutes) : Squats, dumb bell shoulder
exercises, curls, weighted dips, calfs
- tues/thurs lunch: max pull up set then 50 minutes of yoga
- mon-fri afternoon a (10-15 minutes) : pull ups, military press, tricep extensions
- mon-fri afteroon b (10-15 minutes) : rdls, bicep 21's with straight bar, chest fly (stretch mostly)
- everyday (at home): pull up bar whenever I remember
Eventually, I should be rock climbing (primarily bouldering) several nights a week and during the day on saturday/sunday.
Here's my story: 6 month break from all exercise to recuperate from surgery to repair a labral tear (from rock climbing). I have been doing the above routine (basically, a little deviation) for the past four weeks and have been steam-rolling thought my recovery.
IMNHO rest days are only for people that over train a particular muscle to begin with due to obnoxiously long workout routines or through the use of steriods. Unless you fall into that category, focus more on quantity and worry less about going to failure or feeling a 'pump'.
Don't be afraid to try whatever and see how it works for you. To my surprise, this particular routine works best for my physiology and psychology: lots of short medium intensity lifting sessions and a tri-weekly session hard squatting/dead lifting.
=== Update/Clarification ===
I am trying to emphasize a more organic workout routine that is based on how my body feels throughout the day. During each of my 2-5 daily workouts I go in without a set plan (but with a base set of workouts and good idea of my current strength/weaknesses) and randomly pick an exercise. I then move to something else. Depending on what I am feeling strong or weak at, I'll then hammer away at that particular muscle group.
Example:
I go downstairs to my office gym around 10:45 AM. I start off with a quick easy set of wide grip pull ups. Then I grab some 45 weights and do a lap around the gym (farmer's walk?). I focus on how my body feels. Anything sore? If yes, then I'll make sure I don't overdue it when focusing on that that particular muscle group. If i feel somewhat fresh anywhere I'll try burning down that muscle group or do a compound exercise where it's the primary focus.
This particular morning I feel like my chest is a bit sore from yesterday. So I'll do a quick set of chest flies (using a machine), never going past 50% effort and for maybe 10 reps. After that, I notice that my shoulders are feeling a bit too fresh so I immediately start a tri-set of different dumb bell exercises focusing on my shoulder (front raises, side raises, bent over reverse flies). Then I do a set of pull up followed by a quick chest stretch for maybe a 1 minute. Back to the shoulders, immediately followed by another set of pull ups (probably narrow grip or chin up) and a 1-2 minute rest. On more set on the shoulders and then it's back up to my office.
...
It's all about the ebbs and flow. It's not a 'routine' per say, but a lifestyle. Without easy and frequent access to a gym it isn't viable. For me, it's effective and keeps me both mentally and physically engaged throughout the day.
One quick note: I don't recommend this routine for a novice lifter. This style of lifting requires years of experience in the gym to be used effectively and safely.