electron

Look in the acknowledgements section of the papers they publish. There they will indicate funding sources. Make sure to look at their funding for all of their projects because they may not list all of their funding in each paper. Sometimes they will also list their funding on their websites or in their CVs, but not everone does that. (Which reminds me, their CV will also tell you if they have won any big awards or get asked to give important presentations- a few other signs of a good PI) You can also ask, but I wouldn't do that personally. Seems tacky and not very respectful, but I don't know. I should add, look at where former group members have gone on after grad school. If group alumni are frequently getting good positions for post-docs, that really speaks to the PI's abilities as a mentor.

I believe these rankings are based on surveys from people in the field, so you should take them with a grain of salt for that reason alone. But ultimately, what most matters is the professor you work for. Think about it; there are outstanding profs at universities that are ranked lower who may be just as impactful or more as profs at top 5 universities despite being at a smaller or lower impact school. But your PI is the one funding your research, publishing your papers, and writing your recommendation for a post-doc. You should find out the funding and publication records of particular professors you are interested in. That information is far more important than school ranking.

Which Caltech profs called you guys?

I think they're just saying that that's the latest we'll hear back.

Same here. History says we'll get it tomorrow. Bummer.

No email from Yale. Now I'm sad.

That was really funny, but it's a good thing those guys went into chemistry and not acting.

For my main research advisor, I'm only going to get him a gift before I leave his lab. I think the letter is something that is part of the job as a mentor (assuming you deserve it, in which case it is something the advisor is probably more than happy to write). To me, thanking the professor for the letters detracts from my appreciation of his mentorship (as if the all the other little things that might not even be obligations are less important). I think just one big thank you gift for everything is perfect. Obviously that depends on the relationship though. I will probably give my other two letter writers a hand written note and maybe some personalized trinket I think they would appreciate for the letters.