I love the idea of nicely-tinted lips but hate screwing around with reapplying lipstick, smudging it by accident, etc. I tried out three lip stains, which seemed like they were what I was looking for. All three start out a little pale, and then darken as you build up color with reapplications. They're removed by wear during the day, or makeup remover/washing. You won't be able to chug beverages with impunity and not lose some color, so stick to using straws - at least you won't smudge the stain on a straw, unlike with regular lipstick.
The first was Vincent Longo's Lip & Cheek Gel Stain. This is the most expensive of the still-available product lines, but not by much. This looked like applying liquid marker tint rather than an actual gel, with very little tackiness, and dried quickly. If you're using this as a cheek tint, work quickly at blending - apply a little, smudge out, repeat until satisfied. It seemed to be the longest-wearing as well; I was disappointed that the color wasn't more "semi-permanent" but suspect you don't want to be doing anything drastic to your lips/around your mouth if you need to remove a lip color.
The second is the now-discontinued line, MAC Cosmetics' See Thru Lip Colour. (I'm a fan of MAC in general because even though the brand's "look" is waaaaay more dramatic than I'd ever do, the salespeople are always friendly and helpful, even if I'm just buying a single concealer. They encourage recycling their containers by offering a free lipstick if you bring in 6 empty makeup containers to their store, and a particular line of their lip colors, Viva Glam, gives 100% of the purchase price to organizations that help people with AIDS, raising over $70 million so far.) I was thrilled when I found this at a makeup outlet store, but should have guessed something was up - fortunately, the "problem" was just that it was overstock from this discontinued line. Lovely color, but a bit closer to lip gloss in feel, being a thicker gel on application and sticky for longer. It didn't seem to last as long as the Vincent Longo. Came in similar packaging, a long thin tube with a soft-tipped applicator. Still worthwhile if you find it available.
The last is Urban Decay's Lip Envy. I was the least pleased about this product, and don't think it's worth saving the few bucks over buying the Vincent Longo if that other product is available. The bottle shape looks like it's fashioned after an old inkwell with dip pen, with the same fuzzy applicator tip as the other lip stains. This stain was the thickest of any of the three that I tried, and stayed sticky for the longest, requiring a fair amount of time to dry. I typically want my makeup to perform miracles and do it fast, so my opinion of this was that a regular lipstick might be preferable. If you're more patient, it could be worthwhile - but I'd still go with the Longo if you can find it.