I ordered a BNC - banana clips thingy for external triggering. That will, in many cases, free up a probe for something more useful.

Also a SD micro card and adapter–since I eventually want to access it on the SPI bus.

Also, an order into DigiKey:

 1 4 EG4686CT-ND SWITCH SNAP SUB-MINI 70GF 125V 4 Immediate 0 0.93000 $3.72
 2 4 RPC1316-ND BRD SPT SNAP LOCK NYLON 7/8" 4 Immediate 0 0.42000 $1.68
 3 1 478-4059-1-ND CONN SD CARD PUSH-PULL R/A SMD 1 Immediate 0 3.03000 $3.03
 4 1 SER1707-ND OSC XO 8.000MHZ CMOS TTL PC PIN 1 Immediate 0 2.21000 $2.21
 5 1 SER1703-ND OSC XO 4.000MHZ CMOS TTL PC PIN 1 Immediate 0 2.21000 $2.21
 6 2 SAM1112-06-ND CONN HEADER .100" 6POS TIN PCB 0 Immediate 2 Value Add 1.20000 $2.40
 7 1 CP-024B-ND CONN DC POWER RECEPT 5.5 X 2.5MM 1 Immediate 0 2.62000 $2.62
 8 1 CP-024A-ND CONN DC POWER RECEPT 5.5 X 2.1MM 1 Immediate 0 2.84000 $2.84
 9 1 G17S0900110EU-ND CONN DSUB RCPT 9POS STR SLDR CUP 1 Immediate 0 0.86000 $0.86
 10 2 SAM1119-06-ND CONN RCPT .100" 6POS TIN T/H 0 Immediate 2 Value Add 0.80000 $1.60
 11 1 HS411-ND BOARD LEVEL HEATSINK .375"TO-220 1 Immediate 0 0.45000 $0.45