ACER-RELEASED MXM CARDS

I've put the code-names of each card in brackets so you can decipher Acer's cryptic part descriptions on places like AcerParts.com to get the card you want.
EDIT March 2010: Added some part numbers in square brackets for certain cards to prevent ordering the wrong one.

For a brief overview, here are the different types of cards (courtesy of MXM-Upgrade.com):

From left to right: MXM-I, MXM-II, MXM-III, MXM-HE, and MXM-IV (with extra power tab cut off). Smaller cards can fit into larger slots, but not vice-versa.

These are the new MXM 3.0 standards: MXM-A on the left, and MXM-B on the right. These are completely incompatible with the above cards and slots.

Part numbers are in square brackets. Part numbers with a Y as the last digit of the second set of numbers are sourced from Yuan, those with an H are sourced from Foxconn, while those with a 6 are sourced from MSI. Not sure if that impacts compatibility, though.

MXM-I
GeForce 8400M G 128MB DDR2 (NB8M-SE)
GeForce 8400M GS 256MB DDR2 (NB8M-GS)
GeForce 9300M G 256MB DDR2 (NB9M-GE1)
GeForce 9300M GS 256MB DDR2 (NB9M-GS) [VG.9MG06.001] [VG.9MG06.002] [VG.9MG0Y.001]
GeForce 9300M GS 512MB DDR2 (NB9M-GS) [VG.9MG06.003] [VG.9MG0Y.002]

MXM-II
GeForce 8600M GS 256MB DDR2 (NB8P-SE)
GeForce 8600M GS 512MB DDR2 (NB8P-SE)
GeForce 8600M GT 256MB DDR2 (NB8P-GS)
GeForce 8600M GT 512MB DDR2 (NB8P-GS)
GeForce 9500M GS 512MB DDR2 (NB9P-GE1/8PGSH)
GeForce 9600M GS 256MB GDDR3 (NB9P-GE2) [VG.9PG06.007]
GeForce 9600M GS 512MB DDR2 (NB9P-GE2) [VG.9PG06.003] [VG.9PG0Y.004]
GeForce 9600M GT 512MB GDDR3 (NB9P-GS) [VG.9PG06.002] [VG.9PG06.006] [VG.9PG06.008] [VG.9PG0Y.005] [VG.9PG0Y.006]
GeForce 9600M GT 1GB DDR2 (NB9P-GS) [VG.9PG06.009] [VG.9PG0Y.007]
Radeon X2500 256MB DDR2 (M66)
Radeon HD 2300 128MB DDR2 (M71)
Radeon HD 2300 256MB DDR2 (M71)
Radeon HD 2400XT 128MB DDR2 (M74)
Radeon HD 2600 512MB DDR2 (M76)
Radeon HD 3470 256MB DDR2 (M82-XT)
Radeon HD 3470 512MB DDR2 (M82-XT)
Radeon HD 3650 256MB GDDR3 (M86)
Radeon HD 3650 512MB DDR2 (M86)
Radeon HD 3650 1GB DDR2 (M86)
Radeon HD 4570 512MB DDR2 (M92-XT)
Radeon HD 4650 1GB DDR2 (M96) [VG.M9606.005] [VG.M9606.006]

MXM-III
GeForce 9650M GS 512MB GDDR3 (8ESEH)
GeForce 9700M GT 512MB GDDR3 (NB9P-GE/9EGEH))

MXM-A
GeForce GT 130M 1GB DDR2 (N10P-GE1)
GeForce GT 240M 1GB DDR3 (N10P-GS)
GeForce GTS 250M 1GB DDR3 (N10E-GE)
Radeon HD 4530 512MB DDR2 (M92)
Radeon HD 4570 512MB DDR2 (M92-XT)
Radeon HD 4650 1GB DDR2 (M96) [VG.M9606.003] [VG.M960H.001]
Radeon HD 4670 1GB GDDR3 (M96-XT) [VG.M9606.004]

Unknown
GeForce G 105M 512MB DDR2? MXM-A/MXM-II? (N10M-GE1)


OTHER MXM CARDS
These have shown to be compatible with Acer machines. Consider them riskier, but still doable, with MXM-Upgrade.com a step up in compatibility.

MXM-Upgrade.com Cards
Radeon HD 4570 512MB DDR2 MXM-II
Radeon HD 4670 1GB DDR2 MXM-II (replaces their previous HD 4650 offering)
GeForce GTS 250M 1GB DDR3 MXM-A

GeForce 9650M GT 1GB DDR2 MXM-II from ASUS (as shown in above post, this seems to be accepted easily by Acer machines)
Radeon HD 4670 512MB GDDR3 MXM-II from MSI (Failed 6930G Upgrade) (Successful 5920G Upgrade)
Radeon HD 5650 1GB GDDR3 MXM-A from somewhere (see here and here)

For more crazy ideas, check out kisetsu17's post here or niffcreature's here, but note that these are well out of the realm of tried-and-tested.

DISCLAIMER: I am not responsible for any damages to your notebook's functionality by using the information provided here. Proceed at your own risk.