Thanks karl_b. Really useful cheatsheet.
BTW, there's another easy way to check the pin-out and logical pin numbers...
Go to "My Documents/Arduino/hardware/tiny/cores/tiny" and open the file "pins_arduino.c" and one can find nice ASCII text description of the pins, like this in comments...
// ATMEL ATTINY2313
//
// +-\/-+
// (D 17) PA2 1| |29 VCC
// RX (D 0) PD0 2| |19 PB7 (D 16)
// TX (D 1) PD1 3| |18 PB6 (D 15)
// (D 2) PA1 4| |17 PB5 (D 14)
// (D 3) PA0 5| |16 PB4 (D 13)*
// INT0 (D 4) PD2 6| |15 PB3 (D 12)*
// INT1 (D 5) PD3 7| |14 PB2 (D 11)*
// (D 6) PD4 8| |13 PB1 (D 10)
// *(D 7) PD5 9| |12 PB0 (D 9)
// GND 10| |11 PD6 (D 8)
// +----+
//
// * indicates PWM port
// these arrays map port names (e.g. port B) to the
// appropriate addresses for various functions (e.g. reading
// and writing)
In a browser, due to usage of proportional fonts, it might not look great, but in a text-editor with fixed-width fonts, it's just fine.