19) EStrongs File Explorer File Explorer is a local and network file manager that provides a file explorer for both the local phone and your remote computer. You can view files on your phone and in your computer's shared folder and transfer files between them. You can even play audio and video, browse images and view text. Free.
20) Google Voice Streamline and consolidate your phones with this app. It gives you a single phone number that rings all your phones. In addition it saves all your voicemail online and even transcribes your voicemail into text. It offers a host of other features too. Free.
21) Astrid Task Todo List Get yourself organized with this todo list app. It features tagging, timers, reminders, smart task sorting and even tracks partial progress. You can sync your todo list with Remember the Milk, which can sync with Gmail. Free.
22) Thinking Space Thinking Space is a mind mapping application that allows you to visualize, structure and classify ideas. You can create nodes, add notes to them and arrange them, all with a UI that makes it a snap to work with. The maps you create with this app are also compatible with PC-based Xmind and Freemind. Free.
23) Bluetooth File Transfer With this app, you can explore and manage the files on any Bluetooth-enabled device, receive files and send contacts. It's built on FTP and Object Push Profile (OPP).
24) SwitchPro Widget This cool little app gives you the ability to control 17 of your Android phone's functions directly from one of your homescreens. You can turn 3G, Wi-Fi and Bluetooth on and off, adjust your screen's brightness, even reload your SD card after transferring files. Free.
25) Twitter for Android Twitter's branded client is among the best of the Twitter clients available for Android. It hasn't closed the gap with Twitter for iPhone yet, but it's getting there. Free.
26) K-9 Mail An open source project that has taken Google's standard e-mail client and enhanced it, K-9 Mail is a must if you want to do serious non-Gmail-based e-mail management on your phone, especially using IMAP. Free.
27) Facebook The Android Facebook app has its challenges, but it enables account syncing between your Facebook friends and the contacts on your phone. Free.
28) Dolphin Browser HD Don't like the stock browser that came with your Android phone? The Dolphin Browser HD adds a boatload of features, including multiple tab viewing, full multitouch gestures, a thumbnail "flick" menu, gesture-based search and URLs, a YouTube downloader and browser extensions. Free.
29) Opera Mini web browser Looking for more robust browser support? The Opera Mini web browser is super fast and adds features like tabbed browsing, multiple home page tiled Web sites, sync bookmarks between your desktop and phone and more.
30) Evernote This app allows you to log, index and search all manner of information, from notes to audio to photos. For instance, you can take a photo of a white board and Evernote will recognize the text in the photo, index it and then allow you to find it later by entering a search term from the information on the white board. It even synchs with the Web. Free.
31) ActionComplete ActionComplete is a robust task manager. It is built around projects you create, which are made up of individual actions that serve as milestones in the project. The app is based on the Getting Things Done (GTD) methodology created by David Allen in his book: Getting Things Done: The Art of Stress-Free Productivity. Free.
32) Bluetooth File Transfer With this app, you can explore and manage the files on any Bluetooth-enabled device, receive files and send contacts. It's built on FTP and Object Push Profile (OPP). Free.
33) handyCalc Calculator The app adds just about every calculator function you can think of to your Android phone, allowing you to put your scientific calculator in the drawer forever. Free.
34) Seesmic This Twitter client integrates streams from Twitter, Facebook and even Salesforce.com Chatter into a single client, allowing you to stay on top of all your messages from various sources. Unlike many clients, it supports multiple accounts, giving you the ability when composing a message to send it out via one of your accounts or all of them at once. You can also customize a large number of features. Free.
35) Wikidroid Use Wikipedia often? Wikidroid formats Wikipedia articles for your device with a sleek interface. It even includes voice search and bookmarks.