Is beta-alanine or creatine better for recovering from work-outs?

This kind of depends on what you mean by "recovering" from workouts. There is evidence to suggest that the "tear down to build up" theory doesn't hold water.

Creatine seems to maximize anabolic muscle metabolism and therefore builds muscle. If muscle is what you are after, then go for it.

Beta-alanine also helps build muscle, but has a side effect of paraesthesia, (a form of neurogenic pain) with high doses and also tends to be readily excreted in high doses.

With both substances, the form is quite important. Although the synthesis of urea was the death knell to vitalist thinking in the Western medical community many doctors, particularly those influenced by the drug manufacturers, adopted the extreme point of view that synthetics function identically as the original substances.

Many women are finding this NOT to be the case and are finding relief from perimenopausal symptoms using bioidentical hormones rather than the synthetics foisted on them by male doctors in cahoots with corporate synthetic substance pushers.

You may or may not know that synthetic vitamin E blocks the beneficial effects of natural vitamin E. So when you go to the store get "mixed alpha tocopherols" and not "tocopherol acetate." The latter is easier to synthesize and has been touted as a suitable replacement...BUT IT ISN'T.

(Heck. I remember the days when LSD-25 maleate was all you could get and it was mellow felt like reality itself was warping and having some was not yet a federal offense. You had to keep it in the fridge or it would go bad. Then along came LSD-25 tartrate which kept better but gave a jagged trip. No wonder the kids call it "fry.") But I digress...

Verdict: I would tend to go with creatine over beta-alinine for your purposes simply because of the high-dose side-effects. However, I would say that the form of the substance my turn out to be more important than which actual substance, so as asked, I am unable to return a solid verdict.

What's the best book on philosophy written in the past 30 years?

Another question sent in by Aaron. I am called on to make a judgement.

If he had made the range the last 100 years, I would have said Being and Time by Martin Heidegger, with a close second held by the works of Carl Gustav Jung, particularly Memories, Dreams and Reflections, even though he is considered to be a psychologist.

But since it is the last 50 years under consideration, I need to go with Richard Rorty's Contingency, Irony and Solidarity. In a stroke of genius comparable to Einstein's realization that he needed to undo the very foundations of the science of his time, Rorty deconstructs our notions of "truth."

First, he shows that language is contingent rather than absolute, even though we hold it to be absolute when we ask one another whether something said is "true." He contends that within a limited framework such as mathematics statements can be determined to be true or false; but that this does not extend to assertions about reality. He shows further how certain philosophical inquiries create mischief by creating scales on which we can weigh others and determine them to be less valid than ourselves.

Second, he defines what it is to be an ironist:

(1) She has radical and continuing doubts about the final vocabulary she currently uses, because she has been impressed by other vocabularies, vocabularies taken as final by people or books she has encountered; (2) she realizes that argument phrased in her present vocabulary can neither underwrite nor dissolve these doubts; (3) insofar as she philosophizes about her situation, she does not think that her vocabulary is closer to reality than others, that it is in touch with a power not herself.

– Richard Rorty, Contingency, Irony, and Solidarity. Cambridge: Cambridge University Press, 1989, p.73

Finally he examines Solidarity which is the term he uses to describe Us vs Them thinking as a justification for cruelty.

It's just my opinion, but there you are. the best book on philosophy written in the last 50 years.