Assuming I workout on a regular basis and I'm in constant need for protein for recovery.
FWIW, I've been reading the book "Fitness for Geeks" recently, and it says on page 61:
The ability of the body to properly metabolize protein foods diminishes at an intake of about 35 percent of calories, which is why you are not advised to go crazy on protein intake and try to get the majority of your calories from it.
The book cites Shabne, Bilsborough and Neil Mann, “A Review of Issues of Dietary Protein Intake in Humans,” International Journal of Sport Nutrition and Exercise Metabolism, 2006, pp. 1, 129 as the source of that statistic. A Google search for that article led me here.
Protein is about 4 calories per gram, so on a 2000 calorie diet (which would be low for most strength trainers) getting 35% of your calories from protein would mean 2000 / 4 * 0.35 = 175 grams of protein.
I recently stumbled on a great article that talks about protein consumption for the purposes of building muscle (recovery included). It's "The Myth of 1g/lb: Optimal Protein Intake for Bodybuilders". To make a long story short, there was a clinical study to determine how much protein was necessary to build muscle. It is still based on body weight, but the end number they came up with which even supported the highest demands in the study was:
Note that this number is for people who are trying to build muscle. There are other benefits to having protein intake higher than this amount, but they are not related to recovery or building muscle.
If you aren't lifting heavy weights regularly, your protein demands will be lower. If you have no renal issues (no kidney problems), you can safely consume 2g/lb protein. The extra will be converted to energy through a Calorie intensive process or will be defecated out. In short, there is no harm in consuming more protein than your body can absorb, but the benefits aren't related to recovery or building muscle.