We just found an interesting part for power-on reset.

Maxim MAX812:
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$0.60 @ 3000 Reel Qty Future Active.
4 pin SOT143. It has voltage triggered reset by the part order suffix: {4.63, 4.38, 3.08, 2.93, 2.63Vdc}. The package is a little strange - you'll have to make a new PCB layout pad for it.

It also includes a manual reset input that can be driven by TTL or CMOS or a switch to ground (includes internal pullup).

Texas Instruments TPS3825:
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We were looking at the TPS3825 which cost $0.73 @ 3000 Reel qty TI Pricing. Its only advantage is dual polarity reset signals if you have other chips to reset.

No Thanks to External Watchdogs:
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Due to the difficulty of doing FLASH ISP programming with an external watchdog timer, we decided to use the one inside our 89C51 micro.

-Jay C. Box