Glas, you were right, the nightly check was screwing up! I wouldn't have even noticed had you not said anything. Thanks for the heads up!
It's working fine now, and has appropriate limitations that limit the hit on the server to levels that

imagine) are no larger than they'd normally expect. I really don't want this thing to create even a small spike on their server load, and I'll continue to tweak/limit it as needed, or even keep the daily checks limited to those who personally request them. But for now, I think it's able to run as described without causing problems, and I have a limit of daily 50 automatic hits to the server as a cap spread out over 16 hours, just in case.
GlasWolf wrote:
Are these auto-snaps (to coin an expression) just snapshots that are taken and stored on the server but don't appear in the user's snapshot list?
Yes. It will (now, thanks) keep a log of your improvements so you can go back and get a good picture of your track performance over time. I consider this the best of both worlds too

I'm working on creating per-track charts, and I just took a look at the charts that Stulley linked, and I like them.
Stulley, I'm glad you like it! I'm honored, since I've found your tool to be so insanely useful! Mine wouldn't exist had it not been for yours! I'm storing snapshots in mysql since I was sad to see all my old records disappearing. I'm concerned about the XML request too. I've been doing everything possible to cache data, even deadlast's records, so the impact is as transparent as possible. (And yes, the forums are slower, so neither redlynx nor I are taking too much of a hit here.) But it's definitely geared towards on-demand snapshots of your current status for later comparison.
http://highcharts.com/demo/ holy smokes that looks cool. I may just use that! I'll also happily work on some ideas if you have any. I have no qualms about sharing the source for it, aside from the fact that it's grown organically from a pretty utilitarian start (so I know I could have written it much better). One thing I'm curious is how you calculated records from deadlast!
I have this in place now:
90/deadlast's rank = points per track
user points = 100-(rank*points per track)
This works really well to estimate how much you've gained, but when you add the numbers up, they're coming out larger than what you're actually getting. I could just be rounding them too much.
Beyond that, any ideas you have for it are most welcome, and I'll glady play with any ideas to make it better. There's a growing list! Thanks all for the positive/constructive feedback, and long live T2SE
