From nookDevs

The busybox binary is available here, courtesy of and with instructions from http://benno.id.au/

       adb push busybox /data/local 
       adb shell chmod 755 /data/local/busybox 
       adb shell mkdir /data/busybox 
       adb shell /data/local/busybox --install 
       adb shell ln -s /data/local/busybox /system/bin/busybox

You can now play with everything that busybox has to offer, for expample you can kill the browser with

       adb shell /data/local/busybox killall com.android.browser

The above build of busybox states that it has the following functions:

       busybox --help
       
       Currently defined functions:
       [, [[, addgroup, adduser, adjtimex, ar, arp, arping, ash,
       awk, basename, bunzip2, bzcat, bzip2, cal, cat, catv,
       chattr, chgrp, chmod, chown, chpasswd, chpst, chroot,
       chrt, chvt, cksum, clear, cmp, comm, cp, cpio, crond,
       crontab, cryptpw, cut, date, dc, dd, deallocvt, delgroup,
       deluser, df, dhcprelay, diff, dirname, dmesg, dnsd, dos2unix,
       du, dumpkmap, dumpleases, echo, ed, egrep, eject, env,
       envdir, envuidgid, ether-wake, expand, expr, fakeidentd,
       false, fbset, fdflush, fdformat, fdisk, fgrep, find, fold,
       free, freeramdisk, fsck, fsck.minix, ftpget, ftpput, fuser,
       getopt, getty, grep, gunzip, gzip, halt, hdparm, head,
       hexdump, hostid, hostname, httpd, hwclock, id, ifconfig,
       ifdown, ifup, inetd, init, insmod, install, ip, ipaddr,
       ipcalc, ipcrm, ipcs, iplink, iproute, iprule, iptunnel,
       kbd_mode, kill, killall, killall5, klogd, last, length,
       less, linux32, linux64, linuxrc, ln, loadfont, loadkmap,
       logger, login, logname, logread, losetup, ls, lsattr,
       lsmod, lzmacat, makedevs, md5sum, mdev, mesg, microcom,
       mkdir, mkfifo, mkfs.minix, mknod, mkswap, mktemp, modprobe,
       more, mount, mountpoint, mt, mv, nameif, nc, netstat,
       nice, nmeter, nohup, nslookup, od, openvt, passwd, patch,
       pgrep, pidof, ping, ping6, pipe_progress, pivot_root,
       pkill, poweroff, printenv, printf, ps, pscan, pwd, raidautorun,
       rdate, readlink, readprofile, realpath, reboot, renice,
       reset, resize, rm, rmdir, rmmod, route, rpm, rpm2cpio,
       run-parts, runlevel, runsv, runsvdir, rx, sed, seq, setarch,
       setconsole, setkeycodes, setlogcons, setsid, setuidgid,
       sh, sha1sum, slattach, sleep, softlimit, sort, split,
       start-stop-daemon, stat, strings, stty, su, sulogin, sum,
       sv, svlogd, swapoff, swapon, switch_root, sync, sysctl,
       syslogd, tail, tar, taskset, tcpsvd, tee, telnet, telnetd,
       test, tftp, time, top, touch, tr, traceroute, true, tty,
       ttysize, udhcpc, udhcpd, udpsvd, umount, uname, uncompress,
       unexpand, uniq, unix2dos, unlzma, unzip, uptime, usleep,
       uudecode, uuencode, vconfig, vi, vlock, watch, watchdog,
       wc, wget, which, who, whoami, xargs, yes, zcat, zcip