You also have to look at what you are willing to pay but here are my recommendations taking size(mainly since you requested), price, and specs, into perspective
3 MP
1. Canon PowerShot S30
2. Minolta Dimage Xi
3. Minolta Dimage Xt Biz
4. Minolta Dimage Xt
5. Canon PowerShot A75
4 MP
1. Canon PowerShot S45
2. Minolta Dimage F100
3. Canon PowerShot G3
4. Canon PowerShot G2
5. Canon PowerShot A80
5 MP
1. Canon PowerShot S50
2. Canon PowerShot G5
3. Sony Cyber Shot DSC-V1
4. Konica Digital Revio KD-500Z
5. Konica Minolta Dimage G500
Hope this helps.