Some of the useful info when working with ADB on phone

For remounting the system partition as RW on Galaxy SL, (need to be super user)

# mount -o rw,remount -t yaffs2 /dev/block/mtdblock3 /system

For mounting back to RO

# mount -o ro,remount -t yaffs2 /dev/block/mtdblock3 /system

Basic ADB commands

# adb push <local_path> <remote_path>

# adb pull <remote_path> <local_path>

# adb install <path_to_apk>

If you have not installed the cp command may not work, the work around would be 

# cat [source_file] > [destination_file]

The command binaries would be located at this location, /system/bin/ And if you had installed busybox, in /system/xbin/ then first the above path is looked for command, and later the below path.

The /system partition has limited memory, so if you try installing too many applications here, then you may run out of space, and its a better idea to delete many of the unwanted bloat applications from there. I have deleted the following apps and they do not be of much use for me. May be if its not useful for you, you can delete them as well. And you can also delete any other apps which are of no use for you.

1. Samsung Apps [They are meant for Bada, and of no use in Android! wonder why its added here!]
2. BuddiesNow.apk/odex
3. thinkdroid.apk/odex [ThinkFree Office - I have installed Polaris Office instead of this, which is much better]
4. Day.apk/odex
5. DualClock.apk/odex
6. SamsungWidget_Calenderclock.apk/odex
7. SamsungWidget_Feedandupdate.apk/odex
8. SamsungWidget_stockclock.apk/odex
9. SamsungWidget_Weatherclock.apk/odex

All the best, and keep a backup of the file before altering or deleting any file inside /system partition, so that you can restore if something goes wrong, and I am not responsible for any thing if at all it goes wrong :)
Some useful tips and tricks about galaxy S/SL can be found here, its quite long, but when free go through.

Install Busybox on Samsung i9003 Galaxy SL

First of all let me tell me if busy box is needed for you. Mostly it is needed because the adb shell does not have most of the commands supported such cp (copy), and it makes it difficult when you want to modify something (if you have rooted already) difficult because of unavailability of the commands support. So it is preferred to have Busy box, which has most of the command support, and if you had worked in Linux you would know what is busy box for.

Usually, you need to copy the busy box binary on to whichever folder you need, with the help of any command line tool, then say busybox --install, it should setup the links for all the commands and should work for you. And you may need to add that path into you PATH variable. Somehow after long search, I could not find any such thing working for me. 

But now that this application names 'busybox installer' does exactly the same, and it needs root permissions (to make it install in /system/xbin/ ) and you have the option to install any version of busybox you wish to.

So my search ends here (somehow I had seen this before, and dint want to do it this way, wanted to do it manually). One you have installed it, it will automatically restart your phone. Now you have all the comands available on your phone when connected to adb. Some commands may still be taken from old toolbox, and if you specifically need busy box one, you can override it by typing busybox before it. 

Replace ADB Shell With Putty

If your phone is rooted, you need ADB (Android Debug Bridge) for accessing the phone over command line. And when on Windows you may not be comfortable running the Linux command prompt on Windows. You can always run a telnet server on your android phone, and connect using the Putty, but this needs lot of work, and its not an easy option. 

There is an easy option with the help of ADB, you need to have a modified Putty for this, which has the ADB connection type to choose from, and then you can use Putty as you normally use to. Thanks for senior XDA member sztupy. sztupy has compiled a Putty binary with most of the settings pre-set. Here is a snap shot of the same for your reference.

All you need to do is to set the host name to 'transport-usb' as shown and if port number did not come automatically set it to '5037' and you are done. 

Connect the phone using usb cable ans set the debugging mode on, as you normally do to use with ADB, you can enjoy the familiar Putty interface.